Chocolate Cake:
Preheat your oven to 350°F (175°C). Grease and flour three 9-inch round baking pans.
Mix Dry Ingredients: In a large bowl, stir together sugar, flour, cocoa, baking powder, baking soda, and salt.
Add Wet Ingredients: Add eggs, milk, oil, and vanilla. Beat on medium speed for 2 minutes. Stir in boiling water last (batter will be thin). Pour evenly into the prepared pans.
Bake for 30 to 35 minutes or until a toothpick inserted into the center comes out clean. Cool in the pans for 10 minutes, then remove to wire racks to cool completely.
Coconut-Pecan Frosting:
Combine Ingredients: In a medium saucepan, combine sugar, evaporated milk, butter, and eggs. Cook over medium heat, stirring constantly, until thickened, about 12 minutes.
Add Final Ingredients: Remove from heat. Stir in coconut, pecans, and vanilla. Cool until thick enough to spread.
Chocolate Frosting (Optional):
Melt Butter: Melt butter. Stir in cocoa. Alternately add powdered sugar and milk, beating to spreading consistency.
Final Touches: Add a small amount of additional milk, if needed. Stir in vanilla.
Assembly:
Layer Cakes: Place one cake layer on your serving plate. Spread with a layer of coconut-pecan frosting. Add the second layer and repeat. Top with the third layer.
Frost Cake: If you’re using the chocolate frosting, now frost the sides of the cake with it. You can also spread a thin layer on top before adding the final layer of coconut-pecan frosting for a more decadent finish.
Decorate: Use the remaining coconut-pecan frosting to cover the top of the cake. If desired, sprinkle some additional chopped pecans and coconut on top for decoration.
Let the cake sit for a bit before slicing to let the flavors meld together. Enjoy your delicious, homemade German Chocolate Cake!
