INGREDIENTS
3
Egg whites, large
3/4 tsp
Baking powder
1/4 tsp
Baking soda
1 3/4 cups
Cake flour
2 2/3 cups
Confectioner's sugar
1 cup
Granulated sugar
1/2 cup
Rainbow sprinkles
1/4 tsp
Table salt
2 1/2 tsp
Vanilla, pure
1 1/2 cups
Butter, unsalted
2 tbsp
Heavy whipping cream
1/2 cup
Milk
1/2 cup
Sour cream, full-fat