Creating the Red White and Blue Marble Cake is easier than you think! Follow these simple steps to achieve a stunning outcome:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour three 9-inch round cake pans.

2. Mix Dry Ingredients: In a large bowl, sift together the flour, granulated sugar, cocoa powder, baking powder, baking soda, and salt.

3. Combine Wet Ingredients: In another bowl, whisk together the buttermilk, vegetable oil, eggs, and vanilla extract until fully combined.

4. Combine Mixtures: Gradually pour the wet ingredients into the dry ingredients, mixing until the batter is smooth and lump-free.

5. Divide the Batter: Split the batter into three equal parts in separate bowls. Leave one part as is, and dye the second part red and the third part blue using gel food coloring.

6. Layer the Batters: In each prepared cake pan, alternate adding spoonfuls of red, white, and blue batter. Use a knife or skewer to gently swirl the colors together for a marbled effect.

7. Bake: Place the pans in the oven and bake for 25-30 minutes or until a toothpick inserted in the center comes out clean.

8. Cool the Cakes: Once baked, allow the cakes to cool in the pans for 10 minutes before transferring them to wire racks to cool completely.

9. Prepare the Frosting: In a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar and heavy cream, mixing until fluffy. Stir in the vanilla extract.

10. Assemble the Cake: Once the cakes are completely cool, place the first layer on a serving plate. Spread a layer of frosting on top, then add the second layer. Repeat the process, finishing with the third layer on top.

11. Decorate: Frost the top and sides of the cake with the remaining frosting. Top with fresh berries and a drizzle of whipped cream, if desired.

With these steps, you are all set to create your own stunning Red White and Blue Marble Cake!