Preheat oven to 350F (175C).

Line three 9-inch cake pans with waxed paper.

Melt German sweet chocolate in boiling water; let it cool.

Beat egg whites until stiff peaks form; set aside.

In a large mixing bowl, cream butter and sugar until light and fluffy.

Add egg yolks one at a time, beating well after each addition.

Add melted chocolate and vanilla; blend well.

In a medium bowl, sift together cake flour, baking soda, and salt.

Add dry ingredients to chocolate mixture alternately with buttermilk, beating well after each addition.

Fold in egg whites.

Pour batter into prepared cake pans.

Bake for 35 to 40 minutes, or until a wooden skewer inserted into the center comes out clean.

Cool completely in pans before frosting.

For the Coconut-Pecan Frosting: Combine evaporated milk, sugar, egg yolks, and butter in a saucepan.

Cook over medium heat until thickened, about 12 minutes, stirring frequently to prevent scorching.

Remove from heat; stir in vanilla, flaked coconut, and chopped pecans.

Beat until cool and of spreading consistency.

Frost between cake layers and on top of the cake.