Preheat the oven to 176 C or 350 F. Grease two 9" round round cake pans. Line with parchment paper at the bottom, grease and dust lightly over the parchment paper.
Sift the flour, cocoa powder, baking soda, baking powder and salt.
In a bowl, add sugar and the sifted flour mixture and mix well.
In another bowl, add the buttermilk, oil, eggs, and vanilla extract and whisk well. Add these wet ingredients to the dry ingredients and on low speed, mix well. Add the hot coffee mixture and continue to mix on low speed till combined. Do not over mix. Scrape the bottom of the bowl and the sides of the bowl and mix well with a spatula.
Pour the batter into the prepared pans and bake for 35 to 40 mts or till a skewer inserted in the middle of the cake comes out clean.
Cool the cake in the pans for 30 mts and then overturn them onto a cooling rack and cool completely.
While the cake is cooling prepare the ganache. In a stainless steel bowl, add the fresh cream and place on low flame. As bubbles appear along the edges, turn off flame and pour over the grated chocolate. Leave aside for 3 mts. After 3 mts, mix well such that the chocolate completely melts and blends well with the cream.
If the cakes have a dome, slice off the top layer of the dome to achieve a flat cake top. Spread a little ganache in the center of the cake board. Place one cake layer on cake board and place this on a turntable. Using an offset spatula spread a thick layer of ganache all over and place another cake layer with the flat side up on top of it. Spread ganache all over the cake and on the sides. Use a scraper to give a smooth finish all over. Allow to set for half an hour.
To make the remaining ganache of pouring consistency, heat some more fresh cream and add to the ganache and mix well. It should be of pouring consistency. Pour it all over the cake and allow to drip along the sides. You can further garnish with chocolate shard.