Preheat your oven to 350°F (180°C).
Grease and flour three 9-inch round cake pans.
In a large mixing bowl, whisk together the dry ingredients: flour, sugar, cocoa powder, baking powder, baking soda, and salt.
In another bowl, mix the wet ingredients: buttermilk, oil, eggs, and vanilla extract until well combined.
Gradually add the wet mixture to the dry ingredients and mix until just combined. Then stir in the boiling water until smooth.
Divide the batter evenly among the prepared pans and smooth the tops.
Bake for 30-35 minutes or until a toothpick comes out clean from the center.
Allow the cakes to cool in the pans for 10 minutes, then remove and cool completely on wire racks.
In a saucepan, combine coconut, pecans, and heavy cream over medium heat. Cook until thickened, about 10 minutes.
Once thickened, remove from heat and let cool before mixing in confectioners' sugar and chocolate chips until smooth.
Frost the first cake layer and then stack the second on top, repeating the process. Finally, frost the top and sides of the cake.
Garnish with additional coconut and pecans if desired.
Slice, serve, and enjoy the rich flavors of your German Chocolate Cake!