Preheat oven to 350 degrees. Lightly grease two 8-inch cake pans and line with parchment paper.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder and salt. Set aside.
In the bowl of a stand mixer, beat together the eggs, vanilla, coffee, water, veggie oil, and buttermilk until well combined. Slowly add in the flour mix until just combined.
Remove from mixer and fold in the chocolate chips. Divide evenly between two pans and tap to settle. Bake for about 30 minutes, or until a toothpick inserted into the center of the cake comes out clean. Let cool.
In the bowl of your stand mixer, beat the butter until smooth. Add in 3 cups of the powdered sugar, scraping the sides of the bowl to make sure it's well combined.
Add in the vanilla and salt.
Mix in the remaining powdered sugar, adding the heavy cream in as necessary to keep the frosting smooth.
Once your frosting reaches the desired texture, fold in your chopped up dark chocolate and mix well.
Using an angled spatula, frost your cake. Once the frosting is spread evenly across your layers, cover it loosely with plastic wrap and chill in the fridge.
To make the ganache, heat your heavy cream in a small saucepan until just steaming - but not boiling! Add in the chocolate chips and whisk until smooth. Let sit for 15-30 minutes or until thick enough to frost your cake.
Gently pour your ganache over the cake and spread evenly to create a light drip over the cake. Chill and decorate with truffles or your favorite dark chocolate candy! Enjoy.