This fun flag cake recipe not only looks like an American flag on the outside, the inside is also swirled full of red, white, and blue color! It’s the perfect patriotic cake for any red, white, and blue occasion!
Everyone loved my Easter swirl cake so much that I thought it’d be fun to recreate that one with red, white, and blue colors for the fourth of July (or Memorial Day).
And of course I couldn’t stop with a red, white, and blue inside, so I turned the top of a the cake into a flag cake using fruit and a homemade buttercream recipe!
This patriotic flag cake is the perfect addition to any 4th of July party. Serve it up with a little bit of this berry cheesecake fluff on the side of the ultimate dessert spread!
Plus, if the reaction to my previous swirl cake is any indication, this will be a huge crowd pleaser in taste too! It’s really the perfect dessert if you want something easy to make plus a great way to impress people without a ton of effort!
Why You’ll Love This Recipe
- Easy – this cake starts with a box cake mix that’s doctored to taste even better, which means it’s super easy to make! Even the flag on top is super simple!
- Full of surprises – when you first look at the cake, you’d have no idea the inside is actually full of swirled up red, white, and blue color! It’s one of the most fun 4th of July cakes ever!
- Simple flag cake recipe – while other flag cakes out there are a bit complicated to make, this one couldn’t be simpler! It’s just strawberries, blueberries, and a piped rows of frosting!
Ingredients
Ingredient Notes
- White cake mix – any white cake mix will work, I personally used Betty Crocker but it doesn’t matter. If there’s one that’s a moist white cake mix, that would be ideal. You could also use your favorite white cake recipe if you’d like, but know that after all the additions, this one doesn’t even taste like cake mix.
- Clear vanilla – it’s important to use clear vanilla in the batter so that the dark color of regular vanilla doesn’t impact the coloring of the cake. You can get clear vanilla at Walmart, most grocery stores, and on Amazon here.
- Food coloring – I used red and blue food coloring to get those nice bold colors.
- Eggs – I recommend using four egg whites but if you don’t have four eggs, you can also use three whole eggs. You will have a slight yellow tint to the cake but it’ll taste fine.
- Butter – it doesn’t really matter if you use salted or unsalted for the frosting but if you do use salted, I recommend leaving out the added salt. You do want to make sure that the butter is nice and soft before you make this frosting – I like to leave it out overnight or for at least an hour.
- Fresh berries – make sure you’re using fresh and not frozen berries. Fresh fruit is the only real option for this cake! If you don’t like strawberries, you could also do a rows of raspberries instead of the fresh strawberries.
- Powdered sugar – this is also called confectioners’ sugar in the grocery store just as an FYI.
How to make a flag cake
While it looks impressive, this flag cake is actually really easy to make, even the flag part! All you have to do is bake the cake, make the frosting, and decorate the cake.
Sounds simple right? That’s because making this American flag cake recipe really is that simple.
1 – Make the Cake
Preheat the oven to 350°F and grease a 9″ x 13″ baking dish. Alternately, you could also line a baking dish with parchment paper if you’d rather serve the cake outside of the cake pan. Parchment paper makes it simple to take the cake out of the pan once it’s cooled.
In a large mixing bowl (or the bowl of an electric mixer), combine the cake mix, cold water, egg whites, oil, sour cream, and vanilla extract with a whisk attachment. Start mixing on low speed or medium speed until ingredients are combined, then mix on high speed for two minutes, scraping the sides of the bowl as needed.
Now pour two cups of the cake batter into the prepared pan and spread it out evenly. Pour batter throughout the bowl to make it easier to cover the bottom of the baking pan.
Then divide the remaining batter evenly into two separate bowls. Add a few drops of red food coloring to one bowl and a few drops of blue food coloring to the other bowl.
Stir well and add more food coloring until you get the color you want. Once you’re done, you should have three bowls – one with red cake batter and one with blue cake batter.
Drop spoonfuls of colored batter randomly on top of the white cake batter in the cake pan trying to space them out as much as possible while still using all of the batter.
Once you’ve added all of the red and blue cake batter, run a butter knife back and forth through the batter to create swirls of color throughout the white batter.
Don’t do this too much or the colors will start running tonight, 2-3 times is perfect.
Tip!
Swirl the colored batter left to right while gradually going down the pan to ensure that you don’t mix the colors together (not the look you’re going for). Repeat this pattern a couple of times to get the symmetrical swirled look.
Bake for 30 – 35 minutes. Allow cake to cool completely in the pan before frosting. If you frost it too quickly, the frosting will just slide to the sides and be a hot (literally) mess.
2 – Make the Buttercream Frosting
While the cake is cooling make the buttercream by beating the butter until it is light and fluffy. It should change to be at least one shade lighter than it started.
Once it’s light and fluffy, add salt and mix again just to make sure the salt is well incorporated.
Slowly add the powdered sugar a little at a time, mixing on low speed until all powdered sugar is added and mixed well with the butter. You may need to scrape the sides of the bowl to make sure the butter gets mixed in well.
Next, add the clear vanilla and two tablespoons of cream. Beat for one minute and check consistency. If frosting is too thick, add a bit more cream and continue mixing until frosting is a good consistency for spreading.
Unlike some frostings where you’re waiting for stiff peaks to appear, this won’t really get stiff, it’s a softer spreadable frosting.
3 – Decorate the Flag Cake
Frost cake in one even layer, making sure the top of the cake is completely covered and the frosting is smooth. Reserve about one cup of the frosting for decorating and creating your white stripes.
Place five rows of seven blueberries in the upper left corner of the cake. You can adjust the size of the “stars” to your preference so the top of the cake looks like the top of an American flag.
Place remaining buttercream in a piping bag (or a zip-top bag with the corner cut off) with a large star tip or a scallop tip.
Alternate creating red stripes using rows of sliced strawberries and white stripes using buttercream stars (scallops) across the entire cake to complete the flag. The top of cake should look just like an American flag.
Tip!
Place the strawberries all facing the same way to get the most cohesive look of red stripes. You can also choose to use just strawberry slices that are similar in size and eat the others aside from the cake.
4 – Serve the Cake
Serve the cake warm, at room temperature, or even chilled! People will be so excited by the swirled colors inside that they won’t really care what the temperature is (it’s still yummy at all three temperatures).
This is delicious on its own or served with a little homemade raspberry sauce on the side (so you don’t ruin the flag pattern look).
Expert Tips & Storage Info
Store cake in the fridge covered for up to four days. Cake can be served either chilled or at room temperature but the frosting with the heavy whipping cream should be refrigerated.
Switch up the colors and toppings and make this cake work for a different holiday as well! Just make sure to not use more than three colors as more colors can just turn into an ugly mess.
Don’t overdo the food coloring. Food coloring can give have a really strong taste if overused and you really only need a few drops to turn this white cake mix colorful! That’s one of the main reasons you use the clear vanilla – so there are no competing colors!
Have all of your decoration ingredients all sliced and ready to go. You want to ideally add the flag cake decorations as soon as you frost the cake so they can kind of press into them, sealing it all together.
Recipe FAQs
A flag cake is any type of cake that is decorated to look like a flag. Typically most flag cakes are designed to look like an American flag with blue stars and red and white stripes. This cake is a moist white cake with red and blue swirls inside that’s then topped with blueberries, strawberries, and white buttercream frosting to look like an American flag.
This cake freezes beautifully unfrosted. If you know you’re planning to freeze the cake, I recommend placing a piece of parchment paper into the pan before pouring in the batter. Once the cake has baked and completely cooled, pop the cake out of the pan using parchment paper. Wrap it tightly in plastic wrap then freeze for up to three months. If you’ve already decorated the cake, I recommend taking the remaining decorations off and eating those along before freezing.
When you’re ready to eat the cake, remove from the freezer and allow to thaw to room temperature then frost and decorate as instructed.
More Easy 4th of July Recipes
If you like this fun flag cake recipe, make sure to check out these other delicious red, white, and blue recipes!
- Easy patriotic desserts – tons of red, white, and blue desserts that are perfect for patriotic holidays!
- Patriotic mini cheesecakes – red, white, and blue cheesecakes that are absolutely delicious!
- 4th of July rice krispie treats – a fun way to turn a classic treat into something red, white, and blue!
- 4th of July chocolate covered strawberries – red, white, and blue dipped strawberries make a great addition to any 4th of July dessert spread!
- Cheesecake fluff – this red, white, and blue dessert salad is a really fun and delicious dessert for any patriotic party!
Easy Flag Cake Recipe
Ingredients
Cake
- 1 box white cake mix
- ¼ cup water
- 4 egg whites
- ½ cup vegetable oil
- 1 cup sour cream
- 1 tsp clear vanilla extract
- red and blue food coloring
- strawberries (sliced)
- blueberries
Frosting
- ½ cup butter (softened)
- 2 cups powdered sugar
- ¼ tsp salt
- 1 ½ tsp vanilla extract
- 2-4 TBS heavy cream
Instructions
Cake
- Preheat oven to 350°F and grease a 9" x 13" baking dish.
- Combine cake mix, water, egg whites, oil, sour cream, and vanilla in a large mixing bowl or stand mixer. Mix on low speed until ingredients are combined, then beat on medium speed for 2 minutes, scraping the sides of the bowl as needed.1 box white cake mix, 1/4 cup water, 4 egg whites, 1/2 cup vegetable oil, 1 cup sour cream, 1 tsp clear vanilla extract
- Pour 2 cups of the cake batter into the prepared baking dish, then divide the remaining cake batter into two separate bowls. There will be about 3/4 cup batter in each bowl. Add a different color food coloring to each bowl, mix until color is consistent. Use more or less food coloring to get desired color.red and blue food coloring
- Use a spoon to drop dollops of each of the colored batters randomly over the white cake batter in the pan then use a butter knife and run it back and forth through the batter to swirl the colored batter into the white batter. Make sure you don't overdo it or you'll end up with one color instead of swirls.
- Bake the cake until a toothpick inserted in the middle comes out clean, about 30 – 35 minutes. Cool completely before frosting with buttercream.
Frosting
- Beat the butter in a large mixing bowl or stand mixer until it is light and fluffy. Add salt and mix.1/2 cup butter, 1/4 tsp salt
- Slowly add powdered sugar a little at a time, mixing on low speed until all powdered sugar is added and mixed well with the butter. Scrape the sides of the bowl to make sure the butter gets mixed in well.2 cups powdered sugar
- Next, add the vanilla and two tablespoons of frosting. Beat for one minute and check consistency. If frosting is too thick, add a bit more cream and continue mixing until frosting is a good consistency for spreading.1 1/2 tsp vanilla extract, 2-4 TBS heavy cream
- Frost cake, making sure it's smooth. Reserve about 1 cup frosting for decorating.
Flag
- After cake is frosted with buttercream, place 5 rows of 6 blueberries (or enough for the size "stars" you want) in the upper left corner of cake.blueberries
- Place buttercream in a piping bag with a star tip.
- Alternate rows of sliced strawberries and piped buttercream stars across the cake to complete the flag.strawberries
Tips & Notes:
- Clear vanilla – it’s important to use clear vanilla in the batter so that the dark color of regular vanilla doesn’t impact the coloring of the cake. You can get clear vanilla at Walmart, most grocery stores, and on Amazon here.
- Eggs – I recommend using four egg whites but if you don’t have four eggs, you can also use three whole eggs. You will have a slight yellow tint to the cake but it’ll taste fine.
- Butter – it doesn’t really matter if you use salted or unsalted for the frosting but if you do use salted, I recommend leaving out the added salt. You do want to make sure that the butter is nice and soft before you make this frosting – I like to leave it out overnight or for at least an hour.
- Heavy cream – if you don’t have heavy cream, you can substitute milk but you’ll likely only need the two tablespoons since milk is thinner than cream.
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