Step 1Place the cream, sugar and corn syrup in a heavy bottomed, non-reactive saucepan and slowly bring to a boil. Remove from the heat and whisk in the chopped chocolate until it is completely melted and smooth. Whisk in the butter, one piece at a time, and pour into a bowl to cool completely. (At this point, the ganache may be kept covered and refrigerated 3 days.)
Step 2If refrigerated, allow the icing to return to room temperature and stir until smooth before icing the cake.
Step 1Heat the oven to 350 degrees. Butter 2 (10-inch) round cake pans and line with parchment paper.
Step 2Sift together the flour, sugar, cocoa powder, baking soda, baking powder and salt into a large bowl and set aside.
Step 3Place the chopped chocolate in a bowl and pour the hot coffee over. Stir until the chocolate has melted. Set aside.
Step 4Beat the eggs in a mixer at medium speed until light and fluffy, about 2 minutes. Add the oil, vanilla, buttermilk and the coffee-chocolate mixture and mix slowly until combined well.
Step 5Add the dry ingredients and mix on slow speed until combined. Increase the speed to medium and mix for 2 more minutes.
Step 6Pour the batter into the prepared cake pans. Bake until cake tester inserted in center of cake comes out clean, approximately 45 minutes.
Step 7Allow to cool completely, then run a knife around the edge of the pans and turn the layers onto a cake plate.
Step 8Fill and ice the cake with the chocolate ganache icing.