Preheat the oven to 350°F. Butter and flour two 9-inch round baking pans. Set aside.

In a large mixing bowl, whisk together the sugar, flour, cocoa powder, baking soda, baking powder, and salt.

To the mixing bowl, add the eggs, buttermilk, coffee, oil, and vanilla. Using an electric mixer, beat on medium speed for about 2 minutes. You should have a thin batter.

Pour the batter evenly into the prepared cake pans. Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and cool in the pans for 10 minutes; remove cakes from pans to wire racks to cool completely.

Place the chopped chocolate in a medium mixing bowl; set aside.

Place whipping cream and butter in a saucepan and cook over medium heat to just a boil.

Remove from the heat and pour the cream mixture over the chopped chocolate; whisk vigorously until the chocolate is melted and smooth.

Cover and refrigerate for one hour. Remove the frosting from the fridge and stir. Refrigerate for 1 more hour or until spreading consistency.

Spread about 1/4 to 1/3 of the frosting on one cake layer; top with the other cake layer and spread the frosting on top and sides of the cake. Cut and serve.