2 1/2 c. flour
1/2 c. cocoa
1/2 c. water
2 tsp. baking soda
3/4 c. butter
1 3/4 c. sugar
2 eggs
3/4 c. sour milk
1 tsp. vanilla

Add cocoa and soda to water and let stand until rest of cake is mixed. Cream butter and add sugar gradually. Add well beaten egg yolks. Sift flour before measuring and add alternately with milk. Add cocoa mixture. Fold in stiffly beaten egg whites. Add vanilla. Pour into a well greased 9 x 12 inch loaf cake pan and bake in a moderate oven at 350 degrees about 60 minutes.