For the Cake: 

1. Preheat the oven to 350°F. Prepare three 8-inch round baking pans, line the bottom with parchment paper, and grease the sides. Prepare your bake even stripes if desired.
2. In a large mixing bowl, combine the sugar, vegetable oil, eggs, and vanilla extract. Beat on medium speed until the eggs and oil are well incorporated and the batter is lighter in color. Next mix in the sour cream and beat until well combined.
3. In a separate bowl, sift together the dry ingredients. Add half the dry ingredients to the wet ingredients, followed by half of the coffee, and mix until the flour is just incorporated at a low speed. Then add the remaining dry ingredients and coffee. Beat until all of the ingredients are well combined. Use a spatula to scrape down the sides of the bowl and stir the batter from the bottom to the top to ensure it’s well mixed.
4. Divide the batter evenly between the three pans, about 1 2/3 cups of batter per pan. Bake at 350°F for 20-24 minutes.  Test the cake for doneness by inserting a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done. Remove from the oven and allow to cool completely.

For the Frosting: 

1. Cut the butter into pieces. Using the paddle attachment, whip butter for 3-4 minutes, scraping down the bowl occasionally. Beat until the butter looks light in color. Next, beat the peanut butter until well mixed.
2. Alternate adding 2-3 cups of powdered sugar at a time with the liquid ingredients: vanilla extract & heavy cream. Ensure all the powdered sugar is well combined and beat for 2-3 minutes before adding additional powdered sugar.
3. Once all ingredients have been added, whip for 3-4 minutes until the frosting is light and airy. If the frosting is too thick, add additional heavy whipping cream 1 tablespoon at a time. Add a pinch of salt if needed to cut the sweetness.

For the Chocolate Ganache: 

1. In a microwave-safe bowl, combine the chocolate and heavy whipping cream. Melt the chocolate in the microwave at 50% power in 30-second increments and stir until completely combined. Allow to cool.

To Assemble this Cake: 

1. Level the cake layers if needed. Place a dollop of frosting on your cake board and place the bottom layer of cake on top of that. Place half of the frosting in a large piping bag, then cut off the end of the piping bag.  Pipe the first layer of frosting, pipe in circles working outside edge to the middle. Spread evenly with an offset spatula.
2. Add the second layer of cake and add the remaining frosting. Place the third layer of cake on top, and invert the top layer.
3. Use the piping bag to fill in any gaps between the layers and to create a crumb coat. Using an offset spatula or icing smoother, wipe away the excess frosting, leaving you just enough to coat the outside of the cake. With the remaining frosting, proceed to frost the top and sides of the cake using an offset spatula. 
4. Use a spoon or piping bag to drizzle the ganache along the edges of the cake. Use a large piping bag to pipe the rosettes on top. Fill the piping bag with the remaining frosting, and pipe the border of the cake on the top and bottom. Garnish with chopped peanut butter cups.