Preheat your oven to 375°F (190°C) and grease two 8 or 9-inch round baking pans. For easy cake removal, line the bottoms with parchment paper.

In a large mixing bowl, combine the granulated sugar, all-purpose flour, cocoa powder, baking powder, baking soda, and salt. Whisk until well mixed.

In a separate bowl, whisk together the eggs, buttermilk, vegetable oil, and vanilla extract. Combine the wet and dry ingredients, then stir in the boiling water. Note: the batter will be thin, which is perfectly normal for this recipe.

Pour the batter evenly into the prepared pans and bake for 25-35 minutes, or until a toothpick inserted in the center comes out clean. Let the cakes cool in the pans for about 5 minutes before transferring them to wire racks to cool completely.

In a saucepan, combine the light brown sugar, granulated sugar, butter, egg yolks, and evaporated milk. Cook over medium heat, stirring constantly, until the mixture thickens. This should take about 10 minutes.

Remove the saucepan from heat and stir in the vanilla extract, chopped pecans, and shredded coconut. Allow the frosting to cool before using.

In a medium bowl, melt the butter and then stir in the unsweetened cocoa powder until smooth. Gradually add the powdered sugar and evaporated milk alternately, mixing until you reach a smooth consistency. Adjust with more milk or sugar if necessary. Stir in the vanilla extract.

To assemble the cake: Place one cake round on a serving plate. Spread a thin layer of the chocolate frosting on top, followed by half of the coconut frosting. Gently place the second cake round on top and cover the entire cake with the chocolate frosting. Finish by spreading the remaining coconut frosting on top of the cake.

For added flair, sprinkle extra coconut or pecans on top before serving. Enjoy your homemade German Chocolate Cake!