INGREDIENTS
3
Egg whites, large
3/4 tsp
Baking powder
1/4 tsp
Baking soda
1 3/4 cups
Cake flour
1 cup
Granulated sugar
1/2 cup
Rainbow sprinkles
1/4 tsp
Salt
2 tsp
Vanilla extract, pure
1
(120g) full-fat sour cream at room temperature2, full-fat
1
(120ml) whole milk at room temperature2
1/2 cup
Butter, unsalted