INGREDIENTS
8
Egg whites, large
3
Eggs, large
1 3/4 cups
All-purpose flour
1 1/2 tsp
Baking soda
4 oz
Chocolate, unsweetened
1/2 cup
Cocoa powder, Dutch-process
1/2 tsp
Cream of tartar
3 3/4 cups
Granulated sugar
5/8 tsp
Salt, fine
3 1/2 tsp
Vanilla
1 1/2 sticks
unsalted butter, unsalted
1/2 cup
Sour cream
1 1/4 cups
Water