INGREDIENTS
4
Eggs, large
1 1/2 tsp
Baking powder
1/2 tsp
Baking soda
3 1/4 cups
Cake flour
4 cups
Confectioners' sugar
2 cups
Granulated sugar
1 tsp
Salt
2 tbsp
Vanilla
1
Vanilla buttercream frosting
4 sticks
Butter, unsalted very soft
1 cup
Sour cream, full-fat
3/4 cup
Whole milk