For the cake: Preheat oven to 350° F. Line bottom of three 9-inch layer pans with wax or parchment paper. Microwave chocolate and water in large microwavable bowl on HIGH for 1-1/2 to 2 minutes or until chocolate is almost melted. (Microwave times can vary greatly depending on wattage. Always start with less and add more as needed.) Stir until chocolate is completely melted. Mix flour with baking soda and salt; set aside. Beat butter and sugar until light and fluffy. Add egg yolks, one at a time, beating well after each addition. Stir in melted chocolate and vanilla. Add flour mixture alternately with buttermilk, beating after each addition until smooth. Beat egg whites until they form stiff peaks. Gently stir into batter. Pour batter into prepared pans. Bake for 30 minutes or until cake springs back to the touch. Remove from oven; immediately run spatula between cake and sides of pans. Cool in pans 15 minutes. Remove from pans; peel off paper. Cool completely on wire racks. Meanwhile, make the frosting.
For the frosting: Place milk, sugar, egg yolks, butter and vanilla in saucepan. Cook over medium heat, stirring constantly, until mixture thickens and is golden brown, about 12 minutes. Stir in coconut and pecans. Beat until cool and of spreading consistency. Frost cake, spreading frosting between each layer, then on top and sides.
Strong>Notes: If you have a standup electric mixture, use it to make the frosting because it takes forever with a hand held mixer. I found that out the hard way.