INGREDIENTS
1 cup
Blackberries
2
Egg whites, large
2 tbsp
Lemon juice
1 1/4 tsp
Baking powder
1/2 tsp
Baking soda
1 3/4 cups
Cake flour
4 cups
Confectioners sugar
1 cup
Granulated sugar
3/4 tsp
Salt
2 tsp
Vanilla extract
1 stick
Butter, unsalted
2 sticks
Butter, unsalted VERY soft
1/2 cup
Milk
1/2 cup
Sour cream