Julie Clark
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American Flag Sheet Cake (From Scratch, Feeds a Crowd)
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This delicious American flag sheet cake is topped with blueberries and strawberries to create a simple yet patriotic dessert.
Pinterest makes patriotic desserts look easy, but the reality doesn’t always match the photo. Frosting melts, cakes sink in the middle, and even experienced bakers know that festive holiday desserts can be unpredictable.
This American Flag Sheet Cake is the simple solution for the fourth of July. An almond sheet cake, whipped mascarpone topping, and fresh berries are all you need. No special decorating skills required!
American Flag Sheet Cake: A Fun Patriotic Dessert the Whole Family Will Love
Every summer I’m looking for the dessert that I can make the night before and not stress about the day of the party. This sheet cake has become that recipe for me.
The thing I love most is that it looks like a project but isn’t one. The cake itself comes together in one bowl after a quick boil on the stove. The frosting takes about five minutes. And the decorating? Grab the kids because it’s kind of fun. They’ll love laying those strawberry rows down and watching it start to look like a flag.
The almond extract was intentional based on everyone’s love for our almond cream cake. It’s such as simple flavor that pairs well with the fruit.
If you’re planning a full 4th of July spread, this American flag cake pairs really well with strawberry punch or alongside our flag dip and berry icebox cake for a whole patriotic dessert table.
One more thing: this cake is better on day two. Make it the night before, refrigerate it covered, and the flavors deepen overnight. That’s my kind of recipe.
Try our patriotic cake mix jello cookies and patriotic pinwheel cookies, too.
Ingredients Needed for an American Flag Cake
Mascarpone cheese: Look for it near the specialty cheeses or in the deli section of most grocery stores. It’s in a small tub, usually 4 ounces. It should be cold when you start. Use leftover mascarpone in our mascarpone fruit dip and raspberry tarts.
Almond extract: Half a teaspoon is enough to add a noticeable warmth and depth without being too much. If you’re baking for someone with a tree nut allergy, vanilla extract is just fine.
Sour cream: This is what makes the crumb so tender. Full-fat is best here. Plain Greek yogurt works as a swap in a pinch.
Strawberries: Slice them thinly and uniformly so the rows lay flat and look clean. Pat them dry before placing on the frosted cake so the juice doesn’t bleed into the frosting.
Blueberries: Fresh work best. Frozen berries will release too much liquid
See the recipe card for full ingredients and amounts.
How Do You Decorate a Flag Cake with Fruit?
You don’t need a decorating degree for this American flag cake, just a toothpick, patience, and a rough idea of what a flag looks like.
The basic layout:
- The blue canton goes in the upper-left corner, roughly the top ⅓ of the height, left ⅓ of the width of the cake.
- The red stripes run horizontally across the full width of the cake.
- The white “stripes” are just the frosting showing between the strawberry rows.
The toothpick method: Before you place any fruit, use a toothpick to lightly drag an outline of the canton rectangle into the frosting. This gives you a guide so your blueberry section doesn’t drift.
Strawberry placement: Slice strawberries to about ¼ inch thick and lay them in rows, cut side down. They’ll hold their position better and look cleaner than whole strawberries. Gently pat them dry first. Wet berries can make the cake messy.
Blueberry placement: Fill the canton rectangle with blueberries. You don’t need to arrange them in star formation. Placing them casually looks great and is perfectly patriotic.
Tip for clean edges: Use extra berries along the outer border of the flag if you want a more defined look. A row of blueberries around the perimeter of the canton and a row of strawberries along the outer edges of the cake can really sharpen it up.
American Flag Sheet Cake
This delicious American flag sheet cake is topped with blueberries and strawberries to create a simple yet patriotic dessert!
Servings 15
Prep Time 15 minutes
Cook Time 20 minutes
Total Time 35 minutes
Ingredients
For the cake:
- 1 cup salted butter
- 1 cup water
- 2 cups all purpose flour
- 2 cups granulated sugar
- 2 large eggs
- ½ cup sour cream
- ½ teaspoon vanilla extract
- ½ teaspoon almond extract
- ½ teaspoon salt
- 1 teaspoon baking soda
For the frosting:
- 4 ounces mascarpone cheese
- 2 tablespoons granulated sugar
- ¼ teaspoon vanilla extract
- 1 cup heavy cream
- ½ cup blueberries (or more for topping)
- 2 cups sliced strawberries (or more for topping)
Instructions
- Preheat oven to 375ºF. Spray a 10×15- inch pan with cooking spray and line with parchment paper if desired.
- In a large saucepan, bring the water and butter to a boil. As soon as it starts to boil, take the mixture off the heat and let cool for 5 minutes.1 cup water, 1 cup salted butter
- Add this mixture to a large bowl, and combine with the flour, sugar, eggs, sour cream, vanilla, almond, salt, and baking soda. Mix just until combined, scraping the sides of the bowl with a rubber spatula as needed.2 cups all purpose flour, 2 cups granulated sugar, 2 large eggs, ½ cup sour cream, ½ teaspoon vanilla extract, ½ teaspoon almond extract, ½ teaspoon salt, 1 teaspoon baking soda
- Pour the cake batter in the prepared pan and bake in the oven for 16-18 minutes or until the center of the cake springs back when you touch it. Set the cake aside to cool.
- For the frosting, using a whisk attachment, blend the cheese, sugar, and vanilla on low until fully incorporated. Slowly add the heavy cream to the mixture and mix on low, scraping the sides, until it is fully mixed in.4 ounces mascarpone cheese, 2 tablespoons granulated sugar, ¼ teaspoon vanilla extract, 1 cup heavy cream
- Once the cake is cooled, frost the cake. Then use blueberries and sliced strawberries to create the shape of the American flag.½ cup blueberries, 2 cups sliced strawberries
Notes
Store in the fridge, covered in plastic wrap, for 3-4 days. This cake should not be stored at room temperature.
Lemon version: Swap the almond extract for ½ teaspoon lemon extract and add 1 tablespoon lemon zest to the batter. The bright citrus plays beautifully against the fresh berries.
Raspberry stripes: Substitute raspberries for the strawberries. They’re naturally the right size for a stripe and look beautiful.
Boxed cake shortcut: If you need to simplify, a white cake mix made according to the box directions works in this pan. Use the same mascarpone frosting though.
The calories shown are based on the cake being cut into 15 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**
Nutrition
Calories: 401kcal | Carbohydrates: 44g | Protein: 4g | Fat: 24g | Saturated Fat: 15g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 5g | Trans Fat: 0.5g | Cholesterol: 87mg | Sodium: 270mg | Potassium: 90mg | Fiber: 1g | Sugar: 30g | Vitamin A: 806IU | Vitamin C: 12mg | Calcium: 43mg | Iron: 1mg
Can You Make This Cake the Day Before?
Yes, and you should! This American flag cake is a great make-ahead recipe.
What to do: Bake and cool the cake on day one. Make the frosting and frost the cake. Cover tightly with plastic wrap and refrigerate overnight.
When to add the fruit: Add the fruit the morning you will serve it. The berries will release a little juice over time and can start to bleed into the white frosting after sitting for a few hours.
Storage: Once decorated, store covered in the refrigerator for up to 3–4 days. Press plastic wrap directly against the frosting to prevent it from drying out or absorbing fridge odors.
Make it travel-ready: The beauty of a sheet cake is that it goes right in the pan. Cover tightly with foil, transport flat, and you’re set.
Can I use cream cheese instead of mascarpone?
Yes, with a note: the frosting will have a slightly tangier, denser flavor. Use the same amount (4 ounces) and make sure it’s fully softened before beating. The technique for mixing is the same. Be sure to add the heavy cream slowly.
Can I use frozen fruit?
Frozen berries thaw and release too much liquid, which will make the frosting soggy. Fresh is always better here.
How do I keep the mascarpone frosting from getting runny?
Three things: (1) Start the mixer on low speed when you add the cream. High speed too soon can break the mascarpone. (2) Make sure your heavy cream is very cold. (3) Don’t overbeat once it reaches soft peaks. It can go from perfect to grainy quickly. If your frosting looks a little loose, refrigerate the bowl for 10 minutes and try beating again briefly.
