INGREDIENTS
•
1 1/2 cups (3 sticks) unsalted butter, at room temperature, plus more for the pans
•
1 1/2 cups all-purpose flour, plus more for dusting
•
2 3/4 cups cake flour
•
1 tablespoon plus 1/4 teaspoon baking powder
•
1 1/4 teaspoons kosher salt
•
2 1/4 cups sugar
•
6 large egg whites
•
2 tablespoons vanilla extract
•
1 1/2 cups whole milk
•
1 cup plus 2 tablespoons rainbow sprinkles
•
2 cups sugar
•
8 large egg whites
•
3 cups (6 sticks) unsalted butter, cut into pieces, at room temperature
•
1 tablespoon vanilla extract
•
Pinch kosher salt
•
Sprinkles, for decorating