1. Preheat oven to 350°F (175°C). Grease and line two 9-inch pans.

2. Melt German chocolate with boiling water; set aside to cool.

3. Whisk flour, cocoa, baking soda, and salt in a bowl.

4. In a mixer, cream butter and sugar, then add yolks one at a time.

5. Mix in melted chocolate and vanilla.

6. Alternate adding flour mixture and buttermilk, mixing until just combined.

7. Whip egg whites to stiff peaks; fold into batter gently.

8. Divide batter between pans and bake 22–30 minutes. Cool completely.

9. For frosting, combine sugar, milk, butter, and yolks in a saucepan; cook until thickened.

10. Stir in coconut, pecans, and vanilla. Let cool.

11. Spread frosting between layers and on top. Serve.