Melt chocolate in water; cool.
Cream butter and sugar.
Beat in egg yolks.
Stir in vanilla and chocolate.
Mix flour, soda, and salt.
Beat in flour mixture, alternately with buttermilk.
Beat egg whites until stiff peaks form; fold into batter.
Pour batter into three 9-inch layer pans, lined on bottoms with waxed paper.
Bake at 350º for 30 minutes or until cake springs back when lightly pressed in center.
Cool 15 minutes; remove and cool on wire rack.
Frost cake between layers and on the top only, with Coconut-Pecan Frosting.