German Chocolate Cake
["1 (4 oz.) bar Baker's German's sweet chocolate", "1/2 c. boiling water", "1 c. butter", "2 c. sugar", "4 egg whites, beaten stiffly", "4 egg yolks, beaten", "1 tsp. vanilla", "1/2 tsp. salt", "1 tsp. baking soda", "2 1/2 c. plain flour", "1 c. buttermilk"]
["Melt chocolate in boiling water. Cool. Cream butter and sugar until fluffy. Add egg yolks one at a time, beating well after each. Add melted chocolate and vanilla. Mix well. Sift together salt, flour and soda. Add alternately with buttermilk to chocolate mixture; beat until smooth. Fold in egg whites. Pour into three 9-inch layer pans. Bake at 350\u00b0 for 30 to 40 minutes. Cool and frost."]
["chocolate", "boiling water", "butter", "sugar", "egg whites", "egg yolks", "vanilla", "salt", "baking soda", "flour", "buttermilk"]