German Sweet Chocolate Cake
["1 pkg. Baker's German's chocolate", "1 c. butter", "4 egg yolks, unbeaten", "2 1/2 c. sifted Swans Down cake flour", "1/2 tsp. salt", "4 egg whites, stiffly beaten", "1/2 c. boiling water", "2 c. sugar", "1 tsp. vanilla", "1 tsp. soda", "1 c. buttermilk"]
["Melt chocolate in 1/2 cup boiling water; cool.", "Cream butter and sugar until light and fluffy.", "Add egg yolks, one at a time. Beat after each.", "Add vanilla and chocolate; mix until blended. Sift flour, soda and salt and then add dry ingredients alternately with buttermilk to chocolate mixture, beating after each addition until batter is smooth.", "Fold in stiffly beaten egg whites."]
["chocolate", "butter", "egg yolks", "flour", "salt", "egg whites", "boiling water", "sugar", "vanilla", "soda", "buttermilk"]