This chocolate cake with coconut-pecan topping deserves special attention. Cakes require accurate oven temperatures to bake to perfection. In too-hot ovens, cakes may develop tunnels and cracks. A too-cool oven may cause cakes to become coarse.
Separate eggs. Allow egg yolks, egg whites, and butter to stand at room temperature for 30 minutes. Meanwhile, grease and lightly flour two 9x1-1/2-inch or 8x1-1/2-inch round cake pans; set pans aside. Mix flour, baking soda, and salt; set aside.
In a small saucepan combine chocolate and 1/3 cup water. Cook and stir over low heat until melted; cool.
In a large mixing bowl beat butter with an electric mixer on medium to high speed 30 seconds. Gradually add sugar, beating until well combined. Scrape sides of bowl; continue beating for 2 minutes. Beat in egg yolks, one at a time, beating well after each addition (about 1 minute total). Beat in cooled chocolate mixture and vanilla. Add flour mixture and buttermilk alternately to beaten mixture; beat on low speed after each addition until combined.
Thoroughly wash the beaters. In a large mixing bowl beat egg whites with an electric mixer on high speed until stiff peaks form (tips stand straight). Gently fold egg whites into the batter. Spread batter into the prepared pans.
Bake in a 350 degree F oven for 20 to 25 minutes for 9-inch pans. 25 to 30 minutes for 8-inch pans, or until a wooden toothpick comes out clean. Cool cakes on wire racks for 10 minutes. Remove from pans. Cool thoroughly on wire racks. Spread Coconut-Pecan Frosting over tops of cakes, stacking layers. Makes 12 to 16 servings.
In a medium saucepan slightly beat egg. Stir in evaporated milk, sugar, and butter. Cook and stir over medium heat for 6 to 8 minutes or until thickened and bubbly. Remove from heat; stir in flaked coconut and chopped pecans. Cover and cool thoroughly.