The thing with this devil's fudge cake is that the frosting is not frosting, it is sort of fudge. To say it is completely fudge would be misleading. It is in fact a type of ganache. A lot of people are used to seeing the shiny runner ganache, this particular type is a thick type. It is purposely made to set fast and stiff (not hard I mind you) for the purpose of creating a gooey shell of chocolate-love.
1Preheat oven to 350'F
Grease two 9 inch cake pans. Lay parchment circles into the bottoms of each pan, and grease parchment as well.
2Place a medium sized sauce pan over medium heat on the stove. Add black coffee, & butter to the sauce pan and bring it all to a low simmer.
Add cocoa powder and whisk until smooth. Take off the heat and set aside.
3Sift flour, baking powder, and salt together in a large mixing bowl. Set aside.
4In a large bowl with an electric mixer cream sugar and eggs together.
5Add vanilla extract and sour cream to the egg mixture and mix on medium speed until a bit fluffy. About 3 minutes.
6Add cocoa mixture to the egg mixture slowly. Be sure the mixture has cooled enough to where it will not cook the eggs.
Side note: if you are worried it might be a little too warm to add to the eggs, use a whisk to add about a tablespoon of the chocolate mixture to the egg batter and whisk vigorously. This will help temper the eggs to keep them from cooking.
7Add flour mixture to egg mixture in 3rds. Completely incorporate each 3rd of flour before adding next 3rd of flour.
8Pour batter out into the two pans. Bake on a center rack for 35-40 minutes, or until tooth pick comes out MOSTLY clean.
Cool completely on a wire wrack.
9FOR FUDGE ICING:
1- Bring cream to a simmer in a large sauce pan. Once it is to a simmer take it off the heat and add chocolate. Mix until chocolate is completely smooth and melted. Pour out into a large mixing bowl and refrigerate for 2 hours. Mix the icing a little bit every 15 minutes or so.
2- This does take 2 hours to set, so plan your timing out.
1- Once cakes are completely cooled, turn them out.
Level off the tops of each cake, as they are likely to have domed slightly during baking.
Cut each cake in half horizontally. You will have 4 cake layer total.
2- Place one cake layer down on a cake dish or decorating wheel and squirt two tablespoons od chocolate syrup over cake layer. Then spread about 1/2 cup of fudge on first layer. Repeat this until all four layer have been laid. Do not put chocolate syrup on the very top layer however, it'll be frosted for presentation.
3- Once cake is stacked and even spread remaining fudge all over the outside of the cake until smooth. Reserve some if you intend to pipe any of it for decoration like I did.