Preheat the oven to 350°F (175°C).
Grease and flour three 9-inch round cake pans.
Melt the German sweet chocolate in a double boiler and set aside to cool slightly.
In a large mixing bowl, combine the flour, sugar, cocoa powder, baking soda, baking powder, and salt.
In another bowl, whisk together the buttermilk, vegetable oil, eggs, vanilla extract, and melted chocolate.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
Divide the batter evenly among the prepared pans and smooth the tops.
Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
Let the cakes cool in the pans for 10 minutes, then remove and cool completely on a wire rack.
Prepare the frosting by combining the coconut, pecans, evaporated milk, sugar, and butter in a saucepan.
Cook over medium heat until boiling, then reduce to low and stir constantly for approximately 10 minutes until thickened.
Remove from heat and stir in the vanilla extract. Allow frosting to cool before using.
Assemble the cake layers, spreading frosting between each layer and on top and around the sides.
Decorate the top with additional coconut and pecans if desired, and serve.
