DIRECTIONS: In heavy saucepan on low heat, melt broken chocolate with water; set aside. Cream butter with sugar until light and fluffy. Add egg yolks, one at a time beating after each addition. Mix in melted chocolate and vanilla. Sift flour with soda. Add dry ingredients alternately with buttermilk or coffee to chocolate mixture; mix until smooth. Beat egg whites with salt until very stiff peaks form; fold into batter. Spread into three 8 or 9" round cake pans lined with wax paper. Bake at 350-F about 30 minutes. Cool on rack 10 minutes; remove cake.