Preheat your oven to 175°C (350°F). Grease two 9-inch round cake pans and line them with parchment paper.
In a large bowl, sift together flour, sugar, black cocoa powder, baking soda, baking powder, and salt.
In a separate bowl, whisk together eggs, buttermilk, vegetable oil, vanilla extract, and white vinegar.
Pour wet ingredients into the dry mixture and mix until just combined. Slowly stir in the hot black coffee.
Divide batter evenly between prepared pans. Bake for 30-35 minutes until a toothpick inserted in the center comes out clean.
Cool cakes in pans for 15 minutes, then turn them out onto wire racks to cool completely.
Beat cream cheese until smooth, then add powdered sugar and vanilla. Whip heavy cream to stiff peaks and fold into the cream cheese mixture. Refrigerate for 30 minutes.
Heat heavy cream until it simmers, pour over chopped dark chocolate, let sit for 3 minutes, then stir until smooth and add butter. Cool for 20-25 minutes.
Place the first cake layer on a serving plate, spread the vanilla cream cheese filling on top, then add the second cake layer.
Pour ganache over the top, letting it drip down the sides, and press crushed dark chocolate cookie crumbs around the top rim.
Refrigerate for at least 1 hour before slicing and serve cold.
