Espresso fudge frosting
1-In a large bowl, combine dark chocolate,: In a large bowl, combine dark chocolate, semi-sweet chocolate, cocoa powder, butter, espresso powder, vanilla, and salt. Set aside.
2-In a medium pot, combine heavy cream: In a medium pot, combine heavy cream and sugar. Place over medium heat and warm until the sugar dissolves and the mixture is lightly simmering.
3-Pour the hot cream over the other: Pour the hot cream over the other ingredients and whisk together until melted, smooth, and glossy. The frosting will be very runny at this point.
4-Place the frosting into the fridge for: Place the frosting into the fridge for 3-4 hours or until thickened to a spreadable consistency – it usually sets up in the time it takes to make, bake, and cool the cakes, so you could get started on them right away.

Chocolate espresso cake
5-Preheat your oven to 350F: Preheat your oven to 350F. Grease 2 (8″) round cake pans and line the bottoms with parchment paper. Lightly dust the sides with flour and tap out any excess.
6-In a large bowl, whisk together flour,: In a large bowl, whisk together flour, cocoa, granulated sugar, brown sugar, baking soda, baking powder, and salt until combined.
7-Add in the vegetable oil, sour cream,: Add in the vegetable oil, sour cream, eggs, and vanilla. Whisk until streak free. The batter will be quite thick at this point.
8-Measure out 1 cup of boiling water: Measure out 1 cup of boiling water and dissolve instant espresso powder in it.
9-Pour the hot coffee over the thick: Pour the hot coffee over the thick cake batter and whisk until combined.
10-Divide the batter into your 2 cake: Divide the batter into your 2 cake pans.
11-Bake the cakes in the center of: Bake the cakes in the center of your preheated oven for 35-40 minutes or until a skewer inserted into the center comes out clean with a few moist crumbs.
12-Cool the cakes for 10 minutes in: Cool the cakes for 10 minutes in the pans. Then lay a piece of parchment paper over each cake and flip onto a wire rack – this cake is VERY moist, so the parchment paper will help keep it from sticking to your wire rack.
13-Cool the cakes completely to room temperature: Cool the cakes completely to room temperature before layering.

Coffee soak
14-In a small bowl, whisk together boiling: In a small bowl, whisk together boiling water, espresso powder, cocoa, and sugar until everything is dissolved. Set aside for 5-10 minutes to cool to room temperature.

Assemble
15-Before layering the cake, make sure the: Before layering the cake, make sure the frosting has set up to a thick enough consistency to work with. If it hasn’t, keep checking on it in the fridge every 30 minutes until it’s firmed up. If it’s gotten a little too firm, set it out on your counter for a few minutes to allow it to soften.
16-Once the cakes have fully cooled, use: Once the cakes have fully cooled, use a cake leveler or serrate knife to level the tops of the cakes and then slice each cake in half horizontally to create 4 thinner layers.
17-To frost, lay down one cake layer: To frost, lay down one cake layer and then brush some of the coffee soak on top. Spread a thin layer of frosting on top, then repeat this process to stack all the cakes.
18-Lightly frost the outside of the cake: Lightly frost the outside of the cake with a thin layer of frosting to create a crumb coat and seal in the crumbs. Next, chill the cake in the fridge for about 20-30 minutes to allow the crumb coat to harden before covering the outside of the cake with the remaining frosting. Decorate with chocolate curls if desired and keep the cake in the fridge until serving.