01 -
Preheat oven to 350°F (175°C). Generously grease and flour two 9-inch round cake pans.
02 -
In a medium bowl, whisk together all-purpose flour, baking powder, and salt until thoroughly combined.
03 -
In a large mixing bowl, beat softened butter and granulated sugar with an electric mixer until the mixture is pale and fluffy.
04 -
Add egg whites one at a time, beating well after each addition. Blend in the vanilla extract.
05 -
Mix in flour mixture and milk alternately, beginning and ending with flour mix. Stir just until incorporated; do not overmix.
06 -
Divide the batter evenly between two bowls. Tint one portion with pink food coloring and the other with blue. Gently fold in chopped cotton candy into each colored batter.
07 -
Transfer both colored batters into prepared cake pans. Using a knife or skewer, gently swirl for a marbled appearance.
08 -
Bake in preheated oven for 25 to 30 minutes or until a toothpick inserted in the center emerges clean. Allow cakes to cool in pans for 10 minutes before transferring to wire racks to cool completely.
09 -
In a bowl, beat softened butter until creamy. Gradually add powdered sugar, vanilla extract, and 2 to 3 tablespoons milk, blending until a smooth, spreadable consistency is achieved. Divide the frosting and tint half pink and half blue.
10 -
Once cakes are fully cooled, frost with alternating pink and blue frosting. Immediately before serving, decorate generously with additional cotton candy.