Triple Layer Chocolate Cake

1. Preheat oven to 350F. Grease and flour three 9-inch cake pans and place a round of parchment paper in the bottom of each pan. Set aside.
2. In a large bowl, stir together flour, sugar, cocoa powder, baking soda, baking powder, and salt.
3. Add the eggs, buttermilk, coffee, oil, and vanilla extract. Mix on low speed until just combined, scraping down the sides and bottom of the bowl well and stopping when all ingredients just come together. Be careful not to overmix.
4. Divide equal amounts of batter between the pans. Bake on center rack for 30-35 minutes or until a toothpick inserted into the center of a cake comes out clean. Rotate pans about halfway through the bake.
5. Cool in pans for about 10 minutes, and then carefully remove the cakes and allow to finish cooling on cooling racks before assembling and frosting.

Chocolate Buttercream Filling

1. Whip butter using a mixer until creamy. Add melted chocolate and mix until smooth.
2. With mixer on low, add powdered sugar a little at a time, then add vanilla extract and continue mixing until fully combined.
3. Thin frosting with milk or cream, adding a couple of teaspoons at a time and mixing until buttercream is easily spreadable but not too thin.

Shiny Chocolate Ganache Frosting

1. In a bowl, whisk together heavy cream and sour cream.
2. In a medium saucepan, melt butter over medium-low heat. Add sugar, cocoa powder, and salt. Stir to form a paste.
3. Add cream mixture to chocolate and continue cooking while stirring until mixture is totally smooth.
4. Continue stirring over the heat for an additional 5 minutes. Remove from heat and stir in vanilla extract. Remove from heat. Allow to cool for several hours until it reaches a thick, spreadable consistency.

Assembly

1. If your cakes have a significant dome on them, use a large serrated edge knife to carefully cut off the dome. Place a small dollop of frosting on a cake plate, and top with the first cake layer. Add a generous layer of buttercream filling, and then add the second cake layer. Add another layer of buttercream filling. 
2. Place the third cake layer upside down on top of the cake so that the bottom (flattest) part of the layer is on top. Cover the sides and cake with chocolate ganache using an offset spatula or smooth knife. It doesn't have to be smooth - remember the cake from the movie looked a lil messy!
3. Slice and serve. Cake can be kept under a dome for about 24 hours, then should be refrigerated to keep ganache fresh. Allow cake or slices to come to room temp before eating for best texture/flavor.