Lemon Layer Cake

• ¼ pound butter
• ¼ pound sugar
• 3 egg whites

Beat butter and sugar together until light and creamy. Whip egg whites to a stiff froth. Sieve flour with baking powder. Add milk and flour alternately to the butter and sugar mixture. Fold in egg whites and mix very lightly. Pour the mixture into 2 sandwich cake tins which have been greased and lined with paper. Bake in a moderate oven (