This flag cake is not only beautiful, but delicious! A white, almond cake with raspberry filling, and decorated with the best ever sugar cookies. It’s perfect for the 4th of July, Memorial Day, or Labor Day!
A few years ago I wanted to learn to work with fondant, so I decided a 4th of July flag cake would be a good opportunity. I spent hours on that thing. It didn’t turn out exactly how I wanted, but I had a blast doing it.
Since then, I’ve been wanting to make another flag cake. I’ve had so many ideas about how I could make it better. This was the year to put those ideas into action. I present to you, Flag Cake 2018:
Flag Cake 2018 is not decorated with fondant since I believe buttercream is much tastier than fondant. And, I’m pretty sure everyone else thinks that too. Instead of red frosting on the inside of the cake, it has raspberry filling, which is still red, and adds a little something special.
Instead of fondant stars, I made star cookies out of my all time favorite sugar cookie recipe: Sugar Cookies with Royal Icing. Basically, I just look for excuses to make those cookies. If you’re pressed for time, you could always use store bought sugar cookie dough to make the star cookies.
This cake is a version of my White Almond Cake with Raspberry Filling and Buttercream Frosting, except there is no raspberry buttercream. Bottom line: this flag cake is festive, beautiful, and delicious. It takes some time, but is not difficult, and is 100% worth it! Make this and impress everyone when they cut into it and see the fun and surprising inside!
- 1.5 15 ounce packages of white cake mix
- 1.5 cups all-purpose flour
- 1.5 cups sugar
- 1 teaspoon salt
- 2 cups water
- 1.5 cups sour cream
- 3 tablespoons vegetable oil
- 1.5 teaspoons almond extract
- 1.5 teaspoons vanilla extract
- 6 egg whites
- blue and red food coloring
- 12 oz frozen unsweetened raspberries thawed
- 1/2 cup sugar
- 1 tsp lemon juice
- 2 tablespoons cornstarch
- 2 tablespoons raspberry liqueur
- 2 sticks unsalted butter room temperature
- 1 cup all vegetable shortening
- 6-7 cups powdered sugar
- 2 tbsp vanilla
- pinch sea salt
- 6 tablespoons milk or heavy cream
- blue and red food coloring
- Preheat oven to 325 degrees.
- Line three, 8″ round pans and two 6" round pans with parchment paper. Grease and flour the sides (I use baking PAM for this).
- Use a mixer with paddle attachment to beat together water, sour cream, oil, extracts and egg whites until well combined.
- In a separate bowl, whisk together cake mix, flour, sugar, and salt.
- Turn mixer to low. Slow beat cake/flour mixture into sour cream/egg mixture.
- Beat on low for 3-4 minutes. Some lumps will remain.
- Divide batter into 3 bowls. 1/4 of the batter should go into one small bowl and remaining batter should be divided evenly between two medium sized bowls. Use blue food coloring to color batter in smaller bowl until desired color is reached. Use red food coloring to color batter in one of the larger bowl until desired color is reached. Leave the third bowl white.
- Pour blue batter into one of the prepared 8" pans. Pour 2/3 of red batter into one of the 8" pans and the remaining 1/3 into one of the 6" pans. Pour 2/3 of white batter into the final 8" pan and the remaining 1/3 into the remaining 6" pan.
- Bake for 23-28 minutes, or until toothpick inserted into center of cake comes out with just a few crumbs. The thicker cakes will take 25-28 minutes while the smaller cakes will take 23-25 minutes. I put them all in at the same time and check after 23 minutes
- Cool cakes in pans for at least 5 minutes, then remove to racks to finish cooling. Let cool completely before assembling.
- Thaw raspberries and strain juice from berries. For this step I put a large strainer over a bowl and let the berries thaw in the strainer.
- Add enough water to the juice in the bowl so that you have 3/4 cup of liquid.
- Combine juice mixture with sugar, lemon juice, and cornstarch in a small saucepan. Cook over medium heat, whisking constantly, until mixture thickens. Once mixture thickens, remove from heat and set aside.
- Place the raspberries in a mesh strainer. Place strainer over bowl and press berries with spoon so that pulp falls into a bowl. Strain until you have 1/2 cup of pulp.
- Once the mixture in the saucepan has cooled, add the raspberry pulp and raspberry liqueur. Stir well. Transfer to airtight contained and place in refrigerate for at least 3 hours before using.
- Place butter and shortening in bowl of stand mixer fitted with paddle attachment. Beat on medium-high speed until mixture is smooth and has lightened in color.
- Mix in powdered sugar 1/2 cup at a time. Start on low, then beat on high speed until well incorporated.
- Add vanilla and sea salt. Mix until well combined.
- Mix in milk or heavy cream, 1 tablespoon at a time, until desired consistency is achieved.
- Divide frosting into 3 bowls. Place 1/4 of frosting into one bowl and mix in blue food coloring until desired shade is reached. Place 1/4 of frosting into a second bowl and mix in red food coloring until desired shade is reached. Place remaining 1/2 of frosting into final bowl, you will leave this white.
- Use sugar cookie recipe to make sugar cookies, and cut into stars. If you don't want to make sugar cookies, you could use store bought dough and decorate with the royal frosting. I much prefer the homemade though!
- Once cakes have cooled completely, level tops of all cakes. Use a cake leveler or knife to cut 8" red cake, 8" white cake in half (you will then have 4 thin 8" cakes).
- Put an empty 6" pan in the center of the blue cake. Use a knife to gently press down around the pan so that you have an outline of the 6" pan. Remove the pan and cut through the cake along the outline so that you can remove the center of the blue cake (you will not need the center you're cutting out, so you can use it as a snack while you decorate the rest of the cake).
- Place one the 8" red layers on a 10" cake board. Use red frosting to pipe a border along the outside edge of the top of the cake. Fill inside the border with half of the raspberry filling.
- Place an 8" white layer on top of the raspberry filling. Cover layer with white frosting (I used a pasty bag with Wilton tip #12 for this).
- Repeat with next red layer/remaining raspberry filling. Place final white layer on top of this, but do not cover with white frosting. Place red 6" cake on center of white layer. With a Wilton tip #12, use blue frosting to pipe around the red layer. Then place blue layer on top of blue frosting.
- Place final 6" white layer inside of blue layer. For whichever layer is shorter, use corresponding color frosting to raise height to that of taller layer. My white was taller than my blue, so I used blue frosting to pipe on top of the blue cake so that the frosting was the same height as the white cake.
- Divide your white, blue, and red frostings into three pastry bags. Use a Wilton #12, or similar round tip for all of the bags. Start at the bottom of the cake and pipe around the red layer with red frosting, the white layer with the white frosting, etc. Use the blue to color around the blue layer at the top. For the top of the cake pipe around the blue with blue and the middle white with white.
- Use Ateco frosting smoother, or something similar, to go around outside of cake. Just holding the smoother while going around the cake will cause the colors to blend together beautifully. Wipe off the smoother and use it for the top of the cake as well.
- Use the white frosting with the Wilton #12 tip to pipe 8 evenly spaced mounds on the top of the cake. Place a star cookie into each mound. You can also place mounds in the center for a larger cookie as well.
- Change the frosting tip to a Wilton #21, or similar star tip, and pipe stars along the bottom outside of the cake.
- Use sprinkles to decorate further as desired!
Disclaimer: All nutritional information provided on this website is an estimate only and is not guaranteed.
Enjoy this flag cake? You’ll probably enjoy these other SugarSpicesLife recipes:
Chocolate Covered Cherry Cake
Vanilla Cake with Chocolate Buttercream
Lemon Cake with Lemon Oreo Filling
Lemon Strawberry Cake
Amazon items used to make this cake:
- Kitchen Aid Mixer
- Chicago Metallic Professional Non-Stick Round Cake Pan, 8-inch
- Wilton 6″ Round Cake Pan
- Parchment Paper Liners
- Wilton Cake Leveler
- Wilton 10-Inch Carboard Cake Circle
- Wilton Buttercream Tip Set These make buttercream frosting look beautiful.
- Wilton Pastry Bags I use the 12″ bags for almost all frosting … I use them so much that I buy them in bulk
- Wilton Cake Turntable Great when smooth frosting or piping the bottom of cakes.
- Ateco Frosting Smoother I use this when smoothing almost all buttercream cakes