5 egg whites
2 c. sugar
1 c. (2 sticks) butter
3 c. all-purpose flour
3 level tsp. baking powder
1 c. sour milk
1 tsp. vanilla

Beat egg whites, sugar and butter together until creamy. Sift flour and baking powder together 4 times. Gradually add sour milk and beat until smooth. Flavor with vanilla extract. Bake in square, round or rectangular pan in 350°F oven for 45 minutes. Cool, then ice.