Line bottoms of 3 (9 inch) round cake pans with wax paper; grease sides of pans.

Microwave chocolate and water in large bowl on high 1 1/2 to 2 minutes or until chocolate is almost melted, stirring after each minute. Stir until chocolate is completely melted.

Mix flour, baking soda and salt; set aside. Beat butter and sugar in large bowl with electric mixer on Med speed until light and fluffy. Add egg yolks, 1 at a time, beating well after each addition. Stir in chocolate mixture and vanilla. Add flour mixture alternately with buttermilk, beating until well blended after each addition.

Beat egg whites in another large bowl with electric mixer on high speed until stiff peaks form. Gently stir into batter. Pour evenly into prepared pans.

Bake at 350°F for 30 minutes or until toothpick inserted into centers comes out clean. Immediately run knife between cakes and sides of pans. Cool 15 min; remove cake layers from pans. Remove wax paper. Cool completely on rack. Spread Coconut-Pecan frosting between layers and on top of cake. Do not frost sides of a German Choc. cake.