White Chocolate Cake
["4 oz. white chocolate", "1/2 c. boiling water", "1 c. butter or margarine", "2 c. sugar", "4 egg yolks (unbeaten)", "4 egg whites, stiffly beaten", "1 tsp. vanilla", "2 1/2 c. sifted cake flour", "1/2 tsp. salt", "1/2 tsp. baking soda", "1 c. buttermilk"]
["Melt chocolate in boiling water.", "Cool.", "Cream butter and sugar until fluffy.", "Add egg yolks, one at a time, and beat well after each addition.", "Add melted chocolate and vanilla.", "Mix well. Sift together flour, salt and soda.", "Add alternately with buttermilk to chocolate mixture.", "Beat well.", "Beat until smooth. Fold in egg whites.", "Pour into 3 deep 8 or 9-inch layer pans lined with paper.", "Bake in a moderate oven (350\u00b0) for 30 to 40 minutes."]
["white chocolate", "boiling water", "butter", "sugar", "egg yolks", "egg whites", "vanilla", "cake flour", "salt", "baking soda", "buttermilk"]