Preheat oven to 350 degrees F. Butter and line two 7-inch round cake pans.

In a medium bowl whisk flour, sugar, cocoa powders, baking soda, baking powder, and salt until combined.

In a medium bowl combine buttermilk, sour cream, vegetable oil, eggs, and vanilla.

Slowly add flour mixture into the wet mixture and stir until just combined. Add in the coffee and stir until incorporated.

Pour batter into prepared pans and bake for 25-28 mins, or until a toothpick inserted into the center comes out clean. Cool in pans for 10 mins and then turn out onto a wire rack to cool completely.

Place chocolate in a large heatproof bowl.

Warm heavy cream, confectioners sugar, and salt in a pot over medium high heat. Bring to just a boil and then pour over chocolate. Let stand for 5 minutes and then whisk until smooth.

Refrigerate until spreadable, about 1 hour.

Cut tops off of cakes to make flat.

Set one cake layer on a plate. Evenly spread about a ⅓ of ganache over the cake. Top with the other layer of cake. Spread the remaining amounts of frosting over the top and the sides of the cake.

Store leftovers in the refrigerator for 3 days. Bring cake to room temperature before serving.