Sour Cream Cake
["1 c. butter, softened", "3 c. sugar", "6 eggs, separated", "3 c. sifted all-purpose flour", "1 c. sour cream", "1/4 tsp. soda"]
["Cream butter and sugar in a mixing bowl until light and fluffy.", "Blend in egg yolks, one at a time.", "Add sifted mixture of soda and flour alternately with sour cream, mixing well after each addition."]
["butter", "sugar", "eggs", "flour", "sour cream", "soda"]