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This delicious, moist vanilla American flag cake is filled with fresh berries, topped with a light and creamy mascarpone whipped cream, and then crowned with even more fresh berries! I arranged them in honor of the 4th of July but you can adapt to whichever design scheme you’d prefer including an abstract smattering of berries!

An American flag cake made with berries on a marble table

As the weather warms up I find myself gravitation towards lighter cakes and mascarpone whipped cream fulfills that desire in spades! It’s basically a more stable form of whipped cream with a hint of cheesecake flavor.

I highly recommend making using this frosting for all of your favorite cake and cupcake recipes. It’s SO light and dreamy you’ll  delicious cloud is taking a moment to rest on your plate.

How to Make an American Flag Cake

A photo collage showing steps to make an American flag cake.

1. Preheat the oven to 350F. Prepare a 13″ x 9″ sheet cake pan by adding parchment paper. Sift flour, baking powder, salt and granulated sugar. Give it a whisk and set aside.

2. Add egg whites, milk, vanilla, almond extract, and sour cream. Whisk together.

3. Attach a paddle attachment to the stand mixer. Add in room temperature butter and beat until creamy.  On medium speed, beat for the dry into the butter until you get a crumby mixture.

4. Add 1/2 of the wet mixtures. Mix, then scrape the bowl down and add the remaining. Beat until combined. Cut the raspberries in half. Squeeze a little bit of lemon juice over the berries. Add some flour and toss until they’re coated.  Gently fold the raspberries and blueberries into the batter by hand. Pour the batter into the prepared sheet cake pan. Throw in a few more berries. Bake for 35- 40 minutes and/or until a toothpick inserted comes out clean. Let the cake cool to room temperature on a cooling rack.

5. In a stand mixer fitted with a whisk attachment, add heavy whipping cream and confectioners sugar. Beat on high until whipped. Add vanilla extract. Give it another whip on high. Fold in mascarpone by hand using a spatula. Switch to a whisk and beat.

6. Remove parchment paper and I trimmed the sides of the cake. You don’t have to do this, but I wanted a nice fresh edge.

7. Use an ice cream scooper to add the frosting.

8. Smooth with an offset spatula.

9. Using a ruler, I sketched out my flag, then transferred the design to the buttercream. If you’re making an American flag, add blueberries to the top left side of the cake. Add raspberries in lines. Repeat until the flag is finished.

A bite being taken from an American Flag Cake made with blueberries and raspberries

Pro Tips to Make this Berry Cake

  • I used raspberries and blueberries for this cake but you can substitute any of your favorites in. Make sure to cut up larger berries and toss with some flour before folding into the batter.
  • This cake is LOADED with moisture so it will need to bake for a longer time. Everyone’s oven is a bit different so keep an eye on the cake’s center. I will use a skewer and the spring test to make sure the cake is not under-baked.
  • If you want a bit less doming you can fashion your own cake strips wrap them around the edge of the pan. Click here for my full how to on getting flat layers!
  • Don’t over-whip the mascarpone as it may curdle.
  • This cake is best the day of but if you want to make it a day ahead then bake the cake ahead and make the frosting and assemble the day of. 

WHAT IF YOU CAN’T FIND MASCARPONE ANYWHERE?!?

A while back I was making a cake with a mascarpone buttercream and realized mine had expired! I didn’t have time to go to the market so I followed Nigella’s advice for a reasonable facsimile and mixed the following ingredients together until combined. Make sure they are all at room temperature!

  • 8oz cream cheese
  • 1/4 cup heavy cream
  • 2 tbs unsalted butter

If you love this recipe try these out!

Blackberry Lemon Cake

Funfetti Cake

Perfect Vanilla Cake

Summer Berry Cake

If you’ve tried this American Flag cake recipe then don’t forget to leave a rating and let me know how you got on in the comments below, I love hearing from you!

American Flag Cake

Author: John Kanell
Servings: 14 people
Prep Time: 20 minutes
Cook Time: 40 minutes
Total Time: 1 hour
Print Recipe
American Flag Cake made with blueberries and raspberries
4.97 from 31 votes
This American Flag Cake has a moist vanilla sponge filed with fresh berries and topped with a light and creamy mascarpone whipped cream. 

Ingredients 

INGREDIENTS:

For the Cake

  • 2 1/4 cups cake flour 300g, plus a pinch for the berries
  • 1 1/2 cups granulated sugar 342g
  • 1 tsp baking powder heaping
  • 1 tsp kosher salt
  • 1 cup whole milk 240ml, room temperature
  • 1/4 cup sour cream 60ml, room temperature
  • 1 tbsp vanilla extract
  • 6 egg whites room temperature
  • 3/4 cup unsalted butter 176g, room temperature
  • 1 tbsp lemon juice
  • 18 oz raspberries
  • 18 oz blueberries

For the Frosting:

  • 3 cups heavy whipping cream 720ml, cold,
  • 1 cup confectioners sugar 125g
  • 8 oz mascarpone cheese 225g, room temperature
  • 1 tsp vanilla extract

Instructions

For the Cake:

  • Preheat the oven to 350F. Prepare a 13" x 9" sheet cake pan by adding parchment paper.
  • Sift flour, baking powder, salt and granulated sugar. Give it a whisk and set aside.
  • Add egg whites, milk, vanilla, almond extract, and sour cream. Whisk together.
  • Attach a paddle attachment to the stand mixer. Add in room temperature butter and beat until creamy. 
  • On medium speed, beat for the dry into the butter until you get a crumby mixture. Add 1/2 of the wet mixture. Mix, then scrape the bowl down and add the remaining. Beat until combined. 
  • Cut the raspberries in half. Squeeze a little bit of lemon juice over the berries. Add some flour and toss until they're coated.  Gently fold the raspberries and blueberries into the batter by hand.
  • Pour the batter into the prepared sheet cake pan.
  • Throw in a few more berries. 
  • Bake for 35- 40 minutes and/or until a toothpick inserted comes out clean.
  • Let the cake cool to room temperature on a cooling rack.

For the Frosting:

  • In a stand mixer fitted with a whisk attachment, add heavy whipping cream and confectioners sugar.
  • Beat on high until whipped.
  • Add vanilla extract. Give it another whip on high.
  • Fold in mascarpone by hand using a spatula. Switch to a whisk and beat.

For the Assembly:

  • I trimmed the sides of the cake. You don't have to do this, but I wanted a nice fresh edge.
  • Use an ice cream scooper to add the frosting.
  • Smooth with an offset spatula.
  • Using a ruler, I sketched out my flag, then transferred the design to the buttercream.
  • If you’re making an American flag, add blueberries to the top left side of the cake. Add raspberries in lines. Repeat until the flag is finished. 

Notes

This cake keeps really well in the fridge for a few days but as always I loved it most at its freshest, just after frosting it. If you do refrigerate the cake allow it to come to room temperature before eating for best results.
I used raspberries and blueberries for this cake but you can substitute any of your favorites in. Make sure to cut up larger berries and toss with some flour before folding into the batter.
This cake is LOADED with moisture so it will need to bake for a longer time. Everyone's oven is a bit different so keep an eye on the cake's center. I will use a skewer and the spring test to make sure the cake is not under-baked.

Nutrition

Serving: 1piece Calories: 594kcal Carbohydrates: 57g Protein: 7g Fat: 38g Saturated Fat: 23g Cholesterol: 116mg Sodium: 230mg Potassium: 230mg Fiber: 4g Sugar: 36g Vitamin A: 1365IU Vitamin C: 13.8mg Calcium: 114mg Iron: 0.6mg

*Nutrition Disclaimer

Course: Dessert
Cuisine: American

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