This Rainbow Marble Cake is the ultimate showstopper for any occasion. With vibrant swirls of color inside and a rich vanilla buttercream frosting on the outside, it’s a feast for the eyes and the taste buds. Perfect for birthday celebrations, pride events, or any day you want to add a splash of color to the table.
INGREDIENTS- All-purpose flour: 3 cups
- Granulated sugar: 3 cups
- Baking powder: 2 1/2 tsp
- Salt: 1 tsp
- Unsalted butter: 1 cup, room temperature
- Vanilla extract: 2 tsp for cake, 1 1/2 Tbsp for frosting
- Egg whites: 1 cup (about 7 egg whites)
- Buttermilk: 1 1/2 cups, room temperature
- Vegetable oil: 1/8 cup
- Gel food coloring: purple, blue, green, yellow, orange, red
- Butter: 3 cups, room temperature for frosting
- Powdered sugar: 11 cups
- Heavy cream: 1/3 cup
- Salt: 1 tsp for frosting
- Step 1:
- Preheat your oven to 350°F (177°C) and prepare three 8-inch round cake pans by lining them with parchment paper and greasing the sides.
- Step 2:
- In a stand mixer, combine the flour, sugar, baking powder, and salt. Gradually add the butter until the mixture becomes crumbly. Then, add the egg whites and buttermilk, followed by the vanilla extract and oil. Mix until just combined, then beat on medium speed for 30 seconds.
- Step 3:
- Divide the batter evenly into six bowls, and color each bowl with a different gel food coloring. Pour spoonfuls of the different colors into the cake pans and swirl with a knife to create a marble effect.
- Step 4:
- Bake the cakes for 34-37 minutes, or until a toothpick inserted in the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring them to the freezer for 45 minutes to firm up.
- Step 5:
- For the buttercream, beat the butter for 30 seconds, then gradually add powdered sugar, alternating with cream. Mix in the vanilla extract and salt. Adjust the frosting’s consistency with more cream or powdered sugar as needed.
- Step 6:
- Assemble the cake by stacking the layers with a generous amount of buttercream between each. Apply a thin crumb coat, chill, then add a final smooth layer of frosting. Color the remaining frosting and decorate the cake with rainbow stripes using a piping tip.
- For best results, use gel food coloring to maintain the cake and frosting consistency while achieving vibrant hues.
- Store the finished cake in the fridge if not serving immediately, and let it come to room temperature before slicing.
- Spoon and level the flour to ensure the perfect texture for the cake layers. Overmixing can lead to a denser cake, so mix just until ingredients are incorporated.
Tips from Well-Known Chefs
- For a professional finish, use a bench scraper to smooth the buttercream frosting and a rotating cake stand for easier decorating.
If you enjoy this recipe, you may also like Blue Velvet Cake.
