1/2 c. cocoa
1 tsp. baking soda
1/2 c. boiling water
1/2 tsp. salt
1 tbsp. baking powder
2 1/2 c. cake flour, sifted (or 2 1/2 c. minus 2 1/2 tbsp. all-purpose flour,
sifted)
1 c. butter
1 tsp. vanilla
2 c. sugar
4 egg yolks
4 egg whites
1 c. sour milk (you can sour good milk by adding 2 tbsp. of vinegar to 1
c. milk)

Mix 1/2 cup cocoa and 1 teaspoon baking soda. Add 1/2 cup boiling water, stir until smooth and cool.

Grease and flour cake pan(s). Sift together flour, salt and baking powder. Cream 1 cup butter. Add 1 teaspoon vanilla. Gradually add sugar and cream until fluffy. Add egg yolks and beat well. Beat egg whites until stiff.

Combine cocoa and creamed mixture. Add sifted ingredients alternately with sour milk. Mix well after each addition, making sure the last addition is the flour mixture. Fold in beaten egg whites. Bake at 375 degrees for 40-45 minutes or until done.