Preheat oven to 350°. Line two 9" round baking pans with parchment paper, grease and lightly dust with cocoa powder. Set aside.

Whisk flour, sugar, cocoa, baking powder, baking soda and salt together. Set aside.

Mix buttermilk, oil and eggs and vanilla until combined. Slowly add flour mixture to wet mixture until just combined. Pour in hot coffee last and mix until completely smooth. Batter will be very thin, that's okay.

Pour batter into prepared pans and bake for 24-29 minutes or until toothpick comes out moist with only a few crumbs. Let them cool for 20 minutes in their pans then turn them out onto a wire rack to finish cooling completely. While cooling, prepare frosting.

Cream butter, powdered sugar and cocoa powder together until smooth. Add corn syrup and vanilla and mix until just combined. Pour in melted chocolate and beat until smooth and creamy, about one minute. Frosting will be more silky rather than fluffy. BE SURE to add ingredients in this order or your frosting will not come out right!

Once cakes are completely cooled, you can begin to frost them. Theres no need to level the tops of these cakes unless desired. Place one cake layer on plate or cake stand, right side up. Spread the frosting all over in a big, thick layer making sure everything is even. Place second cake layer on top of frosting right side up and frost the rest of the cake evenly. It may help to do a thin crumb coat first, let it set for a few minutes, then go back and do a final thick layer of frosting.

Cake will stay fresh in a sealed airtight container at room temperature for up to 5 days.