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!
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.
Steps to Make this 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.
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!
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
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.
Recipe Video
Recipe 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.
I made this cake yesterday. I’m a beginner baker and have never made a cake from scratch before. I don’t have a stand mixer, but the cake itself was perfect. The whole thing was very delicious and didn’t make me feel like I was eating pure sugar. Mine didn’t come out perfect visually though. My whipped cream was bumpy. I had to use my hand mixer. I was hoping I could have done that part by hand too, but it would have been forever. I should have waited for the cake to cool to room temperature before frosting it, but I was in a rush. I had to stick it in the refrigerator to keep it from becoming soup on top, so I didn’t even get to eat it until this morning. Although it was a learning experience, I’m going to keep using this recipe and I’ll try it in cupcakes, a bundt cake or another sheet cake without the design on top. If this was easier for me to make, I would have given it five stars. I think four is still great. Thank you!
Amarachi,
I’m so happy you liked the cake! Letting your ingredients come to room temperature is always the way to go! I love this recipe because it’s fast and easy to whip up!
John
This is the second recipe I have made and I am 2 for 2! This is a moist, clean cut cake! The cake wasn’t overly sweetened with sugar which let the fruit shine. It was delish for an afternoon snack or even a late night treat! I really enjoyed the luscious frosting. The addition of the mascarpone stabilized the frosting and made it incredibly easy to smooth out! Thanks Jon for knocking another one out of the park.
Latasha,
I am SO happy to hear that you loved the cake! Mascarpone frosting is my obsession right now. Berry season is the best!
John
can you use a carton of egg whites?
I think so, but I haven’t tried it.
This frosting is great and really allows the berry flavors to shine. Great for summer… although I’ll still be in love with it come winter!
Suzanne,
I’m so glad you liked it! It’s the ultimate light frosting!
John
How well do you think this batter would work if it were baked into cupcakes?
This cake was AMAZING!! I followed the icicnt recipe, but it never firmed up. Any tips?
Hey Kate,
I would suggest you to add some more confectioners sugar. Also, sometimes i’ve noticed that different brands of mascarpone cheese perform differently. I hope this works for next time!
Best,
John
Hi John,
I’m so lucky found your blog. I also tried this recipe and it’s amazing! Awsome recipe! Simple to make and the cake is very good.
But it’s too sweet for me. How much sugar I can reduce for this cake? Thanks a lot ^^
I LOVE your enthusiasm for baking! You have inspired me to try your version of many recipes and most of the time, I prefer your recipes over my own! Just proof you can teach this 65 year old grandma new tricks! Keep up the great work!
Made this cake for the 4th of July and it was a hit! I was actually not a huge fan of the berries in it, but I’ll definitely make the cake again! I cut the cake in half and filled it with John’s pastry cream, then topped it with his Swiss Meringue Buttercream. It was amazing!
Moist, delicious, and impressive! I used blueberries and cut up strawberries inside the cake. Love your tips and recipe for mascarpone substitute. I only had regular whipping cream, and it worked well. I was confused by the amount of berries in the cake recipe. I decided 18 oz of each would be too much inside the cake and that it probably was meant to be divided between the baked cake and the top design. Your pictures and video were so helpful, because I don’t like surprises when I’m short on time. It took me about three hours from start to finish. Thank you for making our holiday more special with this recipe. You made me look good!
I made this yesterday for our Fourth of July party and it was quite a hit! I used raspberries, strawberries and blueberries inside the cake and blueberries and raspberries on top. The cake turned out absolutely delicious and the whipped cream frosting was perfectly light and airy and paired well with the cake. I will definitely be making this cake again. Several people also asked for the recipe.
This is the second recipe of yours I have tried. You are 2 for 2! Such awesome flavor and the perfect moistness to the cake! Everyone loved it!