Preheat the oven to 350 degrees F. Grease and flour two 8- to 9-inch round cake pans. Then sift or whisk all dry ingredients in a bowl.
Beat together the eggs, buttermilk, oil, and vanilla. Slowly mix the liquid into the dry ingredients, and beat for two minutes. Once well combined, pour in the hot coffee and mix well. Pour into the cake pans and tap each pan on the counter a few times to remove any large bubbles. Bake for 30-35 minutes, until toothpick inserted comes out clean.
Allow the cakes to cool for 10 minutes, then use the edge of the pan as a guide to cut of the round top. This makes a great mid-cake-baking snack! Run a knife around the edges, and flip out onto a cooling rack. I like to “slam” the cakes out of pan to (hopefully) insure they come out in one piece. Once totally cooled, carefully slice through the middle to make 4 thin round disks. Stack the layers with wax paper in between, then wrap in plastic. Freeze until ready to assemble. Frozen cakes are SO much easier to handle while frosting. It also helps to keep the frosting from getting crumby!
For the Ganache:
Place the chocolate chips in a glass bowl. Heat the cream, butter, and sugar in a small pan. Once the cream is just barely simmering, pour it over the chocolate and allow it to sit for 5 minutes. Then whisk until perfectly smooth. Allow the ganache to cool another 10-15 minutes before assembling layers.
For the Frosting:
Heat the cream in the microwave until hot to the touch, then add the instant coffee to it and mix. Place the cream in the freezer for a few minutes to cool rapidly. Using an electric mixer, mix the melted butter, vanilla and cocoa powder until well combined. Alternate, adding the cooled coffee-cream and powdered sugar until smooth. Add a little more cream or powdered sugar until desired consistency is reached.
Take the cakes out of the freezer. Slather 1/3 of the ganache in between each layer, until all four layers are stacked. Press the top of the cake to level it. Using a large spreader, smooth the frosting around the sides. Then frost the top and re-smooth the edges. Use a damp paper towel to clean up the edges of the cake stand. Place the last bit of the frosting in a piping bag to “fancy-up” the edges, if you want!
Leave the cake out at room temperature so the insides can thaw. Cake tastes better when the frosting and filling are room temperature and soft!