A cake for chocolate lovers: a rich, dense and fudgy three layer chocolate cake, filled and coated with a smooth dark chocolate buttercream, topped with a dramatic ganache chocolate drip. It's crowned with a decorative buttercream rope border for a simple and elegant design worthy of any festive occasion.
Prep Time 30minutes
Cook Time 30minutes
Total Time 2hours
Servings 16" cake with three layers - 12 to 16 slices
Preheat oven to 350° F (177° C, Gas Mark 4). Grease three 6” cake pans and cut circles of parchment paper to place in the bottom of each pan.
In a large mixing bowl, whisk together flour, baking soda, salt and brown sugar. Set aside.
In a medium microwave safe bowl, add butter and cocoa powder. Heat in microwave until butter is fully melted, approximately 60 - 90 seconds. Stir well and add coffee (or water) and whisk to combine. Add eggs one at a time, whisking well between additions to ensure they are fully incorporated.
Add sour cream and vanilla, and whisk until completely blended and batter is smooth. Add dry ingredients and whisk again. Scrape the bowl with a spatula to ensure no flour pockets remain.
Divide the cake batter evenly between the three prepared pans. I use my kitchen scale to ensure that the layers are similar in weight.. Bake in oven for 30-32 minutes, until a toothpick inserted in the middle comes out clean and the cake edges are beginning to pull away from the sides of the pan.
Cool in pans for 10 minutes and then flip onto a metal cooling rack and remove parchment paper. Once fully cooled, use a long serrated knife or a cake leveler to level the tops of the cake layers.
Dark Chocolate Buttercream (Swiss Meringue)
Place the egg whites and granulated sugar into the top of a double boiler over medium heat. Stirring constantly, warm to a temperature of 160 degrees Fahrenheit, or until sugar has dissolved completely. If you rub it between your fingers, you should not feel any graininess.
Remove pot from stove and strain through a fine metal sieve into the bowl of a stand mixer fitted with the whisk attachment. Beat egg white mixture on high speed until glossy, stiff, pillowy meringue peaks form and bowl is cool to the touch – this will most likely take 5 to 10 minutes.
Swap out the whisk attachment for the paddle on your stand mixer. On medium speed, begin adding the butter a few squares at a time, beating until fully incorporated. Continue with this process until all butter has been added and buttercream is thick, creamy, and silky smooth. If the buttercream seems to curdle or turn soupy, keep beating! This is common with ingredients of different temperatures and should right itself if you’re patient. See post for troubleshooting if needed.
Dissolve the espresso powder into the vanilla extract. Add to buttercream along with slightly cooled melted chocolate and kosher salt. Mix on low until completely blended together. Scrape the bowl several times to make sure the chocolate is entirely incorporated into the buttercream.
Chocolate Ganache Drip
In a two quart saucepan, heat cream until almost simmering. Remove from heat and add finely chopped dark chocolate. Let sit for 1 minute, and then gently and slowly whisk until all chocolate has melted and no lumps remain.
Place the first of the three cake layers onto a serving platter. With an offset spatula, spread a generous amount of dark chocolate buttercream onto the entire layer. Cover with the 2nd layer of cake, cut side down. Press down gently. Check for level with each addition. Add another layer of chocolate buttercream. Cover with the 3rd layer of cake, cut side down. Using an offset spatula and a bench scraper, cover top and sides of cake with more buttercream frosting. If you have a cake turntable or a lazy suzan you can place the platter on, it will make this process much easier.
Refrigerate frosted cake for 30 minutes minimum before adding chocolate ganache drip. Test the consistency of your chocolate ganache by doing a practice drip on an upside down quart mason jar or similar container. Ganache should be warm and have a pourable, smooth and fluid consistency.
To add the drip, pour enough chocolate ganache onto the cake to cover the top. Using a mini offset spatula, gently push a bit of the chocolate over the edge in a sweeping motion, following the curve of the cake. This should create a waterfall effect that will push the chocolate over the edge into drips. If needed, add additional chocolate where needed to create extra drip (Note that this will most likely create a second ganache layer - it won't melt into the first drip layer).
Chill cake for an additional 30 minutes to help drip set before adding buttercream rope decoration.
Place the remaining chocolate buttercream in a 16 inch piping bag fitted with an open star tip (I used a 4B piping tip). Hold the piping bag at a 45 degree angle to the top of the cake. Use one hand to squeeze the piping bag, and the other hand to slowly turn the cake turntable away from you. Start your rope on the cake surface. Applying gentle and constant pressure, squeeze piping bag while moving your hand in small counter-clockwise circles - start by moving up and to the right. Continue until you have returned to the starting point. Click for video reference.