American Flag Pie slab dessert on a sheet pan with strawberry and blueberry filling and flaky sour cream crust for Fourth of July — *American Flag Pie is a berry filled sheet pan dessert with a flaky sour cream crust that steals the show at Fourth of July parties.*

This American Flag Pie is a big berry slab pie baked on a rimmed sheet pan with a tender sour cream crust and two fruit fillings that form stars and stripes. The blueberry corner stands in for the field of stars, while juicy strawberries create bright red stripes across the pan. It is made for summer cookouts, Fourth of July, Memorial Day, or any patriotic gathering where you want a dessert that feeds a crowd and doubles as a centerpiece. Even if you are new to slab pies or flag designs, this recipe breaks everything into manageable steps so you can enjoy the wow factor without stress.

Time and Serving

Prep time: about 45 to 60 minutes active work for dough, fillings, and assembly
Cook time: about 60 to 70 minutes total in the oven
Dough chilling time: about 60 to 90 minutes, separate from active prep
Cooling time before slicing: at least 60 minutes at room temperature
Total time: about 3 to 3.5 hours from start to serving
Yield: about 12 generous servings from one standard half sheet pan about thirteen by eighteen inches

Insight of the American Flag Pie

Whole American Flag Pie slab dessert on a sheet pan showing blueberry stars and strawberry stripes for a patriotic party — *A slab style American Flag Pie turns simple berries and crust into a bold stars and stripes centerpiece for patriotic gatherings.*

An American Flag Pie is a slab pie baked in a rectangle pan instead of a round plate. A sour cream based pie dough lines the pan, then two fruit fillings are arranged so that the top of the pie looks like the American flag. The upper left corner holds a rectangle of blueberries for the stars, and the remaining surface is covered with a strawberry filling that becomes the red stripes. Dough cutouts shaped like stars and long strips are laid over the fruit before baking to complete the flag design.

A slab pie is ideal for parties because it bakes in a shallow layer that is easy to portion into neat squares. You get more servings from a single bake, the pieces are simple to lift out with a spatula, and the flat pan travels better in a car than a tall, delicate pie plate. That makes this recipe perfect for potlucks, neighborhood cookouts, and backyard celebrations.

The flag pattern also turns dessert into a conversation piece. People recognize the design as soon as they walk past the table, and it photographs beautifully for holiday photos. You can keep the classic combination of strawberries and blueberries, or swap in other red and blue fruits such as raspberries, cherries, blackberries, or a mix of berries, as long as the corner stays deep blue and the stripes stay mostly red.

Ingredients

These amounts are designed for one half sheet pan about thirteen by eighteen inches.

For the sour cream pie crust

3 1 2 cups about 420 grams all purpose flour
3 1 2 teaspoons granulated sugar
1 1 2 teaspoons kosher salt
14 ounces about 400 grams unsalted butter, cold and cut into small cubes
7 8 cup sour cream this is 3 4 cup plus 2 tablespoons, full fat for best texture

This makes enough dough for the bottom crust plus stars and stripes.

For the strawberry or red fruit filling

3 pounds fresh strawberries, hulled and sliced or quartered
2 3 cup granulated sugar, or a little more if the berries are very tart
6 tablespoons cornstarch or you can use the same amount of quick cooking tapioca or 8 tablespoons all purpose flour
1 tablespoon finely grated orange zest
1 tablespoon fresh orange juice optional

You may replace part of the strawberries with raspberries, pitted sweet cherries, or chopped rhubarb. If you use very juicy fruit such as thawed frozen berries, increase the thickener to 7 or 8 tablespoons total.

For the blueberry or blue fruit filling

2 cups about 300 grams fresh blueberries
1 3 cup granulated sugar
3 tablespoons cornstarch, quick cooking tapioca, or 4 tablespoons all purpose flour
1 teaspoon finely grated lemon zest
2 teaspoons fresh lemon juice
1 4 teaspoon ground cinnamon optional

You can swap in some blackberries with the blueberries as long as the overall look stays dark blue. If your berries are very sweet and firm, reduce the sugar slightly.

For egg wash and finishing

1 egg white
1 tablespoon milk or cream
1 to 2 tablespoons coarse or regular sugar for sprinkling
Whipped cream or vanilla ice cream for serving optional

Required Tools for Making the Recipe

Sheet pan rolling pin bowls star cookie cutter and pastry brush arranged with berries for making American Flag Pie — *A basic rimmed sheet pan, a rolling pin, and a few simple tools are all you need to build this patriotic berry slab pie.*

Rimmed half sheet pan, about thirteen by eighteen inches
Parchment paper to line the pan for easy removal and cleanup
Large mixing bowl for crust
Two medium bowls for the strawberry and blueberry fillings
Measuring cups and spoons and ideally a digital kitchen scale for accuracy
Pastry blender or clean hands for cutting butter into the flour
Rolling pin and a lightly floured work surface
Star shaped cookie cutter, or a small sharp knife to cut stars by hand
Knife or pizza wheel to cut dough into long strips for stripes
Pastry brush for egg wash
Cooling rack to cool the baked pie evenly
Sharp knife or bench scraper for neat squares

If you do not own a star cutter, you will see an easy workaround in the FAQ section.

Method: Step by Step Preparation Guide

Step 01: Make the sour cream pie dough

Cutting cold butter into flour for sour cream pie dough in a mixing bowl for American Flag slab pie — *Start the American Flag Pie with a simple sour cream pie dough, cutting cold butter into flour for flaky layers.*

In a large bowl, whisk together the flour, sugar, and salt.
Add the cold butter cubes and toss them in the flour so they are coated.
Use your fingertips or a pastry blender to work the butter into the flour until most pieces are flattened and the mixture looks like coarse crumbs with some pea sized bits. You still want visible pieces of butter because they create flaky layers in the oven.
Add the sour cream and gently stir with a fork until the dough starts to clump together. If there are dry spots at the bottom of the bowl, drizzle in a teaspoon or two of cold water and keep mixing very lightly.

The dough should feel soft and slightly sticky, but it should hold together when you squeeze a handful. If it looks dry and crumbly, add tiny splashes of water. If it feels very wet, sprinkle in a tablespoon of flour.

Step 02: Divide, shape, and chill the dough

Rectangles of sour cream pie dough wrapped for chilling before rolling for American Flag Pie — *Divide the sour cream dough into three rectangles and chill until firm so it rolls easily and bakes up tender.*

Turn the dough out onto a lightly floured surface.
Gather it with your hands and pat it into a thick rectangle without kneading too much. Overworking can make the crust tough.
Use a bench scraper or knife to divide the dough into three equal portions. Use a scale if you have one for accuracy.
Shape each portion into a rough rectangle about one inch thick.
Wrap each rectangle in plastic wrap or place in a reusable bag and chill for 60 to 90 minutes, or up to one day.

Chilling lets the flour fully hydrate, firms the butter, and makes the dough easier to roll without cracking. Professional bakers strongly recommend this rest for tender, flaky crust, especially with sour cream dough.

If the dough becomes soft or sticky at any point when you are working with it, slide it back into the refrigerator for 5 to 10 minutes before continuing.

Step 03: Prepare the berry fillings

Strawberries and blueberries tossed with sugar and cornstarch in bowls for American Flag Pie berry fillings — *Coat fresh strawberries and blueberries with sugar and starch so the fillings bake into thick, glossy layers.*

Place the sliced strawberries in a large bowl. Add the sugar, cornstarch or other thickener, orange zest, and orange juice if using. Toss gently until every piece of fruit is coated and you no longer see dry clumps of starch.
In a smaller bowl, combine the blueberries with sugar, cornstarch, lemon zest, lemon juice, and cinnamon if using. Stir until evenly coated.

The fruit should look glossy and slightly syrupy rather than dry. Let the bowls sit for about 10 minutes at room temperature while you roll the dough. The sugar will start to draw out some juice, which will blend with the starch and form a sauce that thickens in the oven. Testing from sites such as Serious Eats shows that starches like tapioca and cornstarch create a clear gel when used at roughly 5 percent of the fruit weight, which is why these amounts give slices that hold together without feeling gummy.

Step 04: Roll out and fit the bottom crust

Rolled pie crust fitted into a parchment lined sheet pan with a small dough wall in the corner for American Flag Pie — *Roll the dough to fit a half sheet pan and build a small dough wall in the corner to keep the blue and red fillings separate.*

Line your half sheet pan with parchment paper, leaving some overhang on the long sides if possible.
Take two rectangles of chilled dough from the refrigerator and let them sit on the counter for about 10 minutes so they are firm but workable.
On a lightly floured surface, roll one rectangle into a large oval or rectangle roughly eleven by seventeen inches. Lift and rotate the dough occasionally, dusting under it lightly so it does not stick.
Gently transfer this sheet of dough to the pan, laying it over one half of the base and up the sides with a little overhang.
Roll the second rectangle to a similar size and place it over the other half of the pan, overlapping slightly where the two pieces meet.
Press the seams together so the crust forms one continuous layer. Trim the edges so there is about one inch of overhang around the pan, then fold that overhang inward and crimp it against the rim to create a sturdy border.

Next, create a low wall to keep the blueberries from running into the strawberries. Gather any trimmed scraps and roll them into a rope. Arrange the rope in a rectangle in the upper left corner of the pan and press it down firmly. The wall only needs to be about one half inch high. This simple barrier helps keep the blue and red sections distinct as the fillings bubble in the oven.

Slide the lined and shaped pan into the refrigerator while you work on the top decorations.

Step 05: Shape and chill the stars and stripes

Dough strips and star cutouts on a work surface ready to top an American Flag slab pie — *Cut long strips for stripes and dough stars, then brush with egg wash so they bake up golden and shiny.*

Take the third rectangle of dough out of the refrigerator and let it rest for about 5 to 10 minutes so it will roll without cracking.
On a floured surface, roll it out into a large rectangle about one eighth inch thick. Aim for a longest side that is at least eighteen inches so you can cut long stripes.
Use a knife or pizza wheel to cut several strips about 1 1 2 inches wide. You will want at least two long strips that run the full length of the pan and two shorter ones that span only the strawberry section below the blueberry corner. Cut a few extra strips so you can choose the best ones.
Use a star shaped cutter to cut stars from the remaining dough. Six to nine stars usually look balanced on a half sheet pan, but you can add more if you prefer.
Arrange the stars and strips on a parchment lined baking sheet.

In a small bowl, whisk together the egg white and milk or cream. Lightly brush the stars and strips with egg wash. This will give them shine and help any sprinkled sugar stick. Chill the tray of decorations for at least 20 minutes while you heat the oven. Cold dough keeps its shape better in a hot oven.

Step 06: Assemble the flag design

Unbaked American Flag Pie in a sheet pan with blueberry stars section and strawberry stripes topped with dough cutouts — *Fill the pan with berries and arrange stars and stripes on top so the slab pie looks like the American flag before it bakes.*

Preheat the oven to 450 degrees Fahrenheit with a rack in the lower third of the oven.
Remove the prepared crust from the refrigerator.
Spoon the blueberry filling into the corner section inside the dough wall. Spread it gently into an even layer.
Pour the strawberry filling into the remaining large area and spread it from edge to edge. Try not to disturb the blueberry corner.
Arrange dough stars over the blueberry section.
Lay the long strips across the strawberry section to form stripes, leaving gaps between them so the red filling shows through. Use the shorter strips above and below the blueberry corner so the stripes line up visually.

The flag does not need to have the exact number of stars or stripes to look festive. Slightly wavy strips or stars that are not perfectly spaced actually give the pie a handmade charm.

If the kitchen is warm, place the assembled pie in the refrigerator for about 10 to 15 minutes before baking. This extra chill helps the shapes keep their edges. Professional bakers often chill decorative crusts like this right before baking for a cleaner look.

Step 07: Bake the slab pie

Place the sheet pan on the lower third rack. Bake at 450 degrees Fahrenheit for about 15 minutes. This high heat jump starts browning on the crust and helps the bottom crisp.
After 15 minutes, reduce the oven temperature to 375 degrees Fahrenheit. If the edges or stars are already quite brown, tent the pan loosely with foil so they do not darken too quickly.
Continue baking for another 45 to 55 minutes, or until the crust is deep golden and you see steady bubbling across the surface, especially in the center. Bubbling is a key sign that the starch has cooked enough to thicken the juices.

Check the bottom crust by carefully lifting a corner of the parchment. It should look golden, not pale. If the top is browning too quickly while the bottom still looks light, leave the foil tent on and give the pie a few more minutes.

Step 08: Cool, slice, and serve

Cooled American Flag Pie on a rack with slices cut into squares and served with whipped cream — *Let the slab pie cool so the filling sets, then cut into squares and serve with whipped cream or ice cream for a festive finish.*

Transfer the pan to a cooling rack and let the pie cool at room temperature for at least 60 minutes and ideally up to 2 hours before slicing. This cooling time allows the starch to set the juices so your slices stand tall instead of spilling.
When ready to serve, use a sharp knife to cut neat rectangles or squares. A small offset spatula or thin metal spatula is helpful for lifting the first piece.
Serve plain, or add soft whipped cream or a scoop of vanilla ice cream beside each slice. A light dusting of powdered sugar around the unfilled crust edges can highlight the flag pattern.

Variations

Use raspberries or pitted sweet cherries for part of the red filling. Both fruits stay bright and give deeper flavor. If the fruit is very juicy, add an extra tablespoon or two of thickener.
Fold a small amount of chopped rhubarb into the strawberry mixture for extra tartness. Rhubarb releases more juice, so plan on the higher end of the thickener range.
Mix in some blackberries with the blueberries for a darker blue corner.
For a smaller gathering, bake a half batch in a quarter sheet pan or nine by thirteen inch pan and reduce baking time slightly, checking early since a shallower layer cooks faster.
If you prefer to use store bought pie crust, you will need enough dough for a double crust nine inch pie plus extra, usually three standard rolled crusts. Roll and patch the dough to fully line the pan, and do not roll the dough too thin or it will tear when you lift slices. Baking time is similar, but start checking early since some commercial crusts brown quickly.

Key Advantages of Making American Flag Pie

American Flag slab pie on a holiday buffet table with several slices missing showing an easy crowd pleasing patriotic dessert — *Baked in a sheet pan, this American Flag Pie feeds a full party and slices cleanly into shareable squares.*

Feeds a crowd from one pan, so you do not need to bake several separate pies.
Slices into tidy squares that are easy to serve on picnic plates.
Travels well in the car because the pan is flat and sturdy.
Creates an instant patriotic centerpiece with its star and stripe pattern.
Sour cream crust is tender and forgiving for newer bakers yet impresses experienced guests.
Works with many combinations of fresh summer berries, so you can shop sales or use what your market has.
Can be partly prepared ahead of time which helps keep holiday mornings feel relaxed instead of rushed.

Mistakes to Avoid

Dough too warm when rolling and shaping
If the dough feels sticky, greasy, or slumps when you lift it, it is too warm. Warm dough tears easily and encourages butter to melt before it hits the oven, which leads to less flaky crust. Lightly flour the dough, slide it onto a baking sheet, and chill it for 5 to 10 minutes before you continue rolling.

Not enough thickener in the berry fillings
Juicy berries release a lot of liquid as they bake. If there is not enough cornstarch, flour, or tapioca to absorb that juice, your slices will pool on the plate. Follow the suggested amounts for fresh fruit, and increase the thickener slightly if you are using very ripe or frozen berries. Guidance from tests on mixed fruit and blueberry pies supports using a starch level of about 5 percent of the fruit weight for clean slices.

Skipping the raised barrier between berries
Without that simple dough wall in the corner, the blue and red fillings can run together as they bubble, which blurs the flag design. Take a moment to roll a rope of dough and press it firmly in place. It will almost disappear under the berries but makes a big difference in the final look.

Overbaking or underbaking
An underbaked slab pie can have pale, doughy crust and thin, watery filling. Overbaking can scorch the edges and dry out the fruit. Use visual cues rather than time alone. The crust should be deep golden, and the filling should bubble across the surface, not just at the edges. If the top is browning too quickly, protect it with foil while the center finishes cooking.

Cutting the pie before it has cooled
It is very tempting to slice into the pie while it is still hot, especially when it smells amazing. If you cut too soon, the hot filling will spill and the slices will collapse. For neat squares, let the pie cool until it is warm but not steaming. You can always warm individual pieces later in a low oven if you like them warm.

Expert Tips Real Life Examples

For planning and timing
On busy holiday weekends, I often make the dough the day before and store it in the refrigerator. In the morning I roll the crust, prepare the fillings, and cut the stars and stripes. Sometimes I even cut the stripes the night before and chill them on a baking sheet so they are ready to go. This spreads the work out into small jobs rather than one long session.

For serving different styles of gatherings
For a casual backyard barbecue, I cut the slab into twelve generous rectangles and let guests pick up slices with a spatula. For a sit down dinner, I make smaller rectangular portions, sometimes sixteen pieces, and set them on dessert plates with a small scoop of ice cream. The flat shape makes both options easy.

For transport
When I bring this pie to a friend, I cool it completely in the pan, then cover it loosely with foil so the crust does not soften. The whole pan slides into a large reusable grocery bag or cooler bag. Because it is shallow, it rides well on the back seat.

For design and texture
Chill the assembled pie for about 10 to 15 minutes before baking so the stars and stripes keep their edges. Brush all visible dough with egg wash and sprinkle a light layer of sugar for shine and a little crunch.

For adjusting thickener and sweetness
If your berries are very sweet and firm, you can reduce the sugar by a tablespoon or two. If they taste quite tart, increase the sugar slightly. Taste a piece of fruit before you add the starch. Once the starch goes in, avoid tasting because raw starch is unpleasant. For frozen berries, add one extra tablespoon of cornstarch to each filling to account for the extra water they release as they thaw.

Nutrition Facts (Per Serving)

These values are approximate and based on the amounts above, divided into twelve servings. Numbers will vary with different brands and any changes to the recipe.

Calories: about 520 per serving
Total fat: about 30 grams
Carbohydrates: about 60 grams
Protein: about 6 grams

The fruit contributes fiber and natural sweetness, while most of the fat comes from the butter in the crust. If you want slightly lighter slices, cut smaller pieces and serve with plenty of fresh berries on the side.

Frequently Asked Questions

Q1: Can I use frozen berries instead of fresh for American Flag Pie

Yes, you can use frozen berries, but there are two important adjustments. First, do not thaw the berries completely they can go in still partially frozen. Second, add one to two extra tablespoons of cornstarch to each filling to handle the extra liquid that frozen fruit releases. Expect the pie to need a few extra minutes in the oven.

Q2: How far in advance can I bake this slab pie before serving

For best texture, bake the pie the same day you plan to serve it, ideally within about 6 to 8 hours. According to guidance based on USDA information, fruit pies that do not have custard or cream can stay at room temperature for up to about two days if loosely covered, after which they should be refrigerated. I like to serve this pie on the day it is baked and enjoy leftovers chilled on the next day.

Q3: What can I do if I do not have a star cookie cutter

You have several options. You can use a small sharp knife to cut simple star shapes by hand or trace around a paper star. You can also cut small rectangles or circles and arrange them in the blueberry corner in a loose star field pattern. Even rustic shapes look charming once the pie is baked.

Q4: How do I prevent the bottom crust from getting soggy

Start with a fully chilled crust that goes into a hot oven. Baking on the lower third rack of the oven helps the bottom crust receive more direct heat. That first high temperature phase at 450 degrees Fahrenheit helps set the crust quickly before the juices have time to soak in. Make sure you bake until the filling is bubbling and the bottom looks golden when you peek under a corner of parchment.

Q5: Can I make a smaller version for a family of four

Yes. Halve all of the ingredients and bake the pie in a quarter sheet pan or nine by thirteen inch pan. The method is precisely the same, although the baking time will be slightly shorter since the filling layer is a bit thinner. Start checking at about 35 to 40 minutes after you lower the oven temperature and bake until you see firm bubbling across the center.

Conclusion

Nearly empty American Flag Pie pan on an outdoor table at the end of a Fourth of July party with plates and crumbs around it — *By the time the fireworks start, this American Flag Pie is usually down to the last few slices and everyone is asking for the recipe.*

American Flag Pie brings together a tender sour cream crust, a generous layer of berries, and a bold star and stripe design that looks right at home on any patriotic table. The slab pie format makes it easier to serve a crowd, carry to a party, and slice into neat squares. Once you understand the basic steps chilling the dough, thickening the fillings correctly, building a simple dough wall for the blueberry corner, and giving the pie time to cool this dessert becomes a reliable showstopper for every Fourth of July.

Start with the classic strawberry and blueberry version, then once you feel confident, play with other red and blue fruit combinations and different decorative touches on top. With a little planning and these step by step instructions, you will have a festive flag pie that tastes every bit as good as it looks.