Whimsical Cotton Candy Cake with Swirled Layers

Ingredients

• 2 1/2 cups all-purpose flour
• 2 1/2 teaspoons baking powder
• 1/2 teaspoon kosher salt
• 1 cup unsalted butter, softened
• 1 3/4 cups granulated sugar
• 5 large egg whites, room temperature
• 2 teaspoons vanilla extract
• 1 cup whole milk
• 1 cup cotton candy, chopped, plus extra for garnish
• Pink food coloring
• Blue food coloring
• 4 cups powdered sugar
• 1/2 cup unsalted butter, softened
• 2 to 3 tablespoons whole milk
• 1 teaspoon vanilla extract