Combine the cream, butter, sugar, egg yolks and vanilla in a medium saucepan.
Cook and stir the mixture over medium heat until it is thick (about 12-15 minutes).
Add the coconut and pecans. Mix well and allow to cool.
Once the mixture is at room temperature, beat the mixture for 2-3 minutes. Set aside.
For the Cake:
Preheat oven to 350 degrees. Grease and flour 3 round 8-inch cake pans.
For the cake, put flour, sugar, cocoa, baking powder, baking soda and salt in a bowl and mix well.
In a stand mixer, mix the buttermilk, oil, eggs, vanilla together. Slowly add in the mix of dry ingredients while the mixer is on low. Add the coffee and make sure everything is combined. The batter will be very thin.
Divide the batter between the prepared pans and bake for about 23-25 minutes or until a toothpick inserted in the middle comes out clean.
Allow the cakes to cool on a wire rack for 10 minutes. Turn the cakes out onto a cooling rack.
For the Buttercream:
In a stand mixer with the beater blade, beat the butter for 1-2 minutes until it is smooth, creamy and nearly white in appearance.
Add in the salt and vanilla. Mix until incorporated.
With the mixer on low speed, slowly add in the powdered sugar and cocoa powder.
Add the heavy cream, a tablespoon at a time, mixing slowly until it is the consistency that you'd like.
Beat for 1 minute on medium speed until smooth and creamy.
Assemble the Cake:
Frost the top each cooled cake layer with the coconut pecan frosting.
Stack the layers together. Then frost around the outside of the cake with chocolate buttercream.
Pipe stars using Wilton tip 1M on the top outer edge of the cake.
Store in an airtight container in the refrigerator.
The calories shown are based on the cake being cut into 12 pieces, with 1 serving being 1 slice of cake. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate.