Ultimate Rainbow Cake.
3/4 cup all-purpose flour.
3/4 cup cornstarch.
6 large egg whites.
6 large egg yolks.
1 1/2 tsp vanilla extract.
3/4 cup + 6 tbsp sugar.
1/4 tsp salt.
2 cups unsalted butter, room temperature.
1 tsp vanilla extract.
5 cups confectioner?s sugar
pink, orange, yellow, green, blue and purple food coloring
Let's get Cooking...
Beat the egg yolks, vanilla extract and 3/4 cup sugar with an electric mixer on high speed until thick and pale. Set aside.
In a separate bowl, beat the egg whites and salt with an electric mixer on medium speed until soft peaks form. Slowly add the remaining 6 tbsp sugar and beat until stiff, glossy peaks form.
Gently fold the egg white mixture into the egg yolk mixture. Combine the flour and cornstarch in a small bowl, then add to the egg mixture in 3 additions.
Divide the mixture into 6 bowls and dye each bowl of batter a different color. Be sure to gently fold the food coloring in ? you want to keep the batter as airy as possible.
Pour the batter into 6 greased and flour 9-inch round cake pans. Bake at 350F for about 5 minutes, until the cakes are fully cooked. Transfer the cakes to a wire rack and allow them to fully cool.
Make the buttercream: Place the butter in a bowl and whip with an electric mixer until pale and fluffy. Add the vanilla extract and mix to combine. Add the confectioner?s sugar one cup at a time, mixing well with each addition. Then whip for 3-5 minutes, until fluffy.
Set 1/3 of the buttercream aside. Divide the remaining buttercream into 6 bowls and dye them the colors of the rainbow. Place each color in a piping bag fitted with a star-shaped piping tip.
Using a plate as a stencil, cut the edges off each layer of cake. This will give the cake a clean look and make layering much easier.
Place the purple layer of cake on a serving platter of your choice and spread some of the white buttercr...