I may have gone a little overboard, but when asked to make an over-the-top rainbow cake for AwesomenessTV, I couldn’t resist! This rainbow, lollipop, drip cake is made with my favorite vanilla cake base, my american buttercream, and white chocolate ganache drips. The full recipe and instructions can be found below:
Rainbow Vanilla Cake:
- 3 1/4 cup flour
- 3 cups granulated sugar
- 2 1/2 tsp baking powder
- 1 tsp salt
- 1 cup unsalted butter (2 sticks), room temperature
- 3 tsp. vanilla extract
- 1 cup egg whites (about 7 large egg whites)
- 1 1/2 cups buttermilk, room temperature
- 1/8 cup vegetable oil
- red, orange, yellow, green, blue, and violet gel food coloring
Vanilla Frosting:
- 6 sticks (3 cups) unsalted butter, room temperature
- 12 cups powdered sugar
- 1/2 tsp salt
- 3 Tbsp. heavy cream
- 3 tsp vanilla
Colored Drips:
- 1/2 cup heavy cream (about 4 oz.)
- 1 1/2 cups white chocolate chips (9 oz.)
- red, orange, yellow, green, blue, and violet gel food coloring
- plastic squirt bottles
Instructions:
Preheat oven to 350°F. Grease and line six 7” round pans.
Mix together all dry ingredients (flour, baking powder, sugar, and salt) in a stand mixer with a paddle until fully combined.
Mix chunks of room-temperature butter slowly into the dry mix, on a low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.
Pour in egg whites, and mix on low until just incorporated. Mix in the buttermilk in two installments, on a low speed. Add in vanilla and oil, and mix at a low speed until fully incorporated. Scrape down the sides of the bowl with a spatula, then beat on medium high for about 30 seconds.
Divide evenly between six bowls, and color each bowl a different color. Pour the batter into the prepared cake pans. Bake for 30-32 minutes, or until a skewer comes out clean. Allow to cool for 10 minutes, then run an offset spatula around perimeter of the pan to separate the cake from the pan. Place cake layers on a rack to finish cooling.
While the cake layers bake and cool, prepare the frosting. Beat the butter on high for 30 seconds with a paddle attachment, until smooth. Slowly add in the powdered sugar, 1 cup at a time. Alternate with small splashes of cream. Once fully mixed, add in the vanilla and salt, and beat on medium low until the ingredients are fully incorporated, and the desired consistency is reached. If the frosting is too thick, add in cream (1 teaspoon at a time). If the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).
NOTE: When making frosting for a cake, it is important to mix the buttercream on low at the end of the process for a couple minutes, to get out any extra air that might have be incorporated during the mixing process. This will make it easier to get super smooth sides on your cake!
Once the frosting is prepare, make the white chocolate ganache. Heat heavy cream in a heat-proof bowl in the microwave for 45 seconds-1 minute, until bubbling. Gently pour white chocolate chips into the heavy cream, making sure they are fully covered with cream. Allow mixture to sit for 2 minutes. Stir slowly until the cream and white chocolate are combined, then heat again for 20 seconds and stir. Repeat as necessary until all the chocolate bits are fully melted and incorporated. If it seems too thin or thick, you can add a touch more chocolate chips or heavy cream! The type of cream and white chocolate that you use can affect the consistency, so feel free to adjust as needed.
Divide evenly between six bowls, then add gel food coloring. Allow to cool until desired viscosity is reached. Pour into plastic squirt bottles. I like to put my ganache into plastic squirt bottles when decorating cakes! But you can also use a spoon to drizzle it over cakes. Extra ganache can be kept in the fridge for 2 weeks.
Once the cake layers are fully cooled, assemble the cake. Stack and frost layers with buttercream, in color order (ROYGBV).
Apply a thin crumb coat, and chill the cake in freezer for 5 minutes. Once the crumb coat is firm to the touch, apply, a second, thicker coat of frosting. Smooth with a bench scrapper. If you want to see a full tutorial for how I get smooth sides on my cakes, you can click here. Place cake in freezer for 15 minutes. Once the cake is fully chilled, divide the top of the cake into six equal triangles. Use squirt bottles to add the ganache drips, making each color one triangle. You can learn all the tips and tricks I use to add drips to a cake here.
Next, place colorful lollipops and candies on top of the cake. I matched the color of the candy to the color of the drips.
