1 3/4 c. sifted all-purpose flour
1 tsp. double-acting baking powder
1/2 tsp. baking soda
1/4 tsp. salt
1/2 c. unsweetened cocoa powder
1 stick butter
1 tsp. vanilla
1 3/4 c. granulated sugar
4 eggs, separated
1 1/4 c. milk

Preheat oven to 325 degrees. Sift flour, baking powder, baking soda, and cocoa. In large bowl cream butter; add vanilla and sugar; beat well. Add egg yolks; beat well.

On low speed add dry ingredients alternately with milk. Beat egg whites until they hold shape but are not stiff or dry. Fold whites into chocolate mixture.

Grease 2 (10 inch) cake pans and line with wax or liner paper. Butter paper and dust with a little flour. Pour batter into pans. Bake about 45 minutes or until cake begins to come away from sides of pans. Let stand 4-5 minutes. Invert and remove paper lining.

FROSTING:

6 oz. unsweetened chocolate
1 c. plus 2 tbsp. granulated sugar
3 tbsp. plus 2 tsp. water
3 sticks butter
1/2 tsp. vanilla
2 tbsp. unsweetened cocoa powder
3 lg. eggs

In small saucepan dissolve sugar and water over moderate heat; stir constantly with wooden spoon until sugar is dissolved and mixture comes to fast boil. Add chocolate which has been chopped into small pieces; stir over heat until chocolate is melted and mixture is smooth. Remove from heat; let stand 5 minutes, stirring occasionally.

Cream butter; add vanilla and cocoa; beat well. Add eggs one at a time, beating after each addition. On low speed gradually add chocolate mixture; beat only until smooth.

Place this bowl in a larger bowl filled with ice and water; stir mixture constantly until thick as mayonnaise. If it thickens unevenly, remove from water and stir until it smooths out. Return to ice; continue to stir to reach mayonnaise thickness. Frost cake layers.