German Sweet Chocolate Cake
["2 1/2 c. sifted cake flour", "1 tsp. soda", "1/2 tsp. salt", "1 pkg. Baker's German's sweet chocolate", "1/2 c. boiling water", "1 c. margarine", "4 egg yolks (unbeaten)", "1 tsp. vanilla", "2 c. sugar", "1 c. buttermilk", "4 egg whites"]
["Measure sifted flour; add soda and salt.", "Sift again.", "Melt chocolate in boiling water; cool.", "Cream butter and sugar until fluffy.", "Add yolks, one at a time, beating after each.", "Add chocolate and vanilla.", "Add flour mixture alternately with buttermilk, beating after each addition until smooth.", "Beat egg whites to stiff peaks.", "Fold into batter."]
["cake flour", "soda", "salt", "chocolate", "boiling water", "margarine", "egg yolks", "vanilla", "sugar", "buttermilk", "egg whites"]