This cake is a sweet-toothed chocolate lover’s dream. Basically an Irish Car Bomb in cake form, it’s my completely over-the-top dessert of choice this year for St. Paddy’s Day, even though I can only eat a few bites before my body tells me it can’t take any more. Ethnically insensitive drink names aside, those few bites are delicious, especially if you’ve made sure to use good quality chocolate for both the cake and the ganache. Because this cake is so rich, it feeds several- up to 32 people, I’d wager- making it great for a crowd or for a dessert that you want to stretch over several days of company.
Inspired by a recipe from Confessions of a Tart
For the cake:
1 1/2 cup unsalted butter (3 sticks)
1 1/2 cup Irish stout
1 cup +2 tablespoons natural cocoa powder
3 cups flour
2 1/4 cup sugar
2 teaspoons baking soda
1 1/4 teaspoon Kosher salt
3 large eggs
1 cup sour cream
For the ganache filling:
8 oz bittersweet chocolate, chopped into very small pieces
8 oz heavy cream
2 tablespoons butter, at room temperature
2 teaspoons whiskey
For the Irish buttercream
4 sticks butter, at room temperature
8-10 cups confectioner’s sugar
1/2 cup Bailey’s Irish Cream (for a milder flavor, replace half of this with milk or cream)
For the ganache glaze (optional)
6 oz bittersweet chocolate, chopped into very small pieces
8 oz heavy cream
Make the cake:
1. Preheat oven to 350°. Butter and flour three 9″ cake pans and set aside.
2. In a medium saucepan, melt the butter, then add the Guinness and heat until simmering. Remove from the heat, add the cocoa powder, and whisk until combined.
2. While the butter melts, mix the flour, sugar, baking soda, and salt in a large bowl. In a medium bowl, whisk together the eggs and sour cream. Once the Guinness mixture is finished, add it to the eggs and sour cream and whisk until combined.
3. Add the wet ingredients to the dry ingredients, then whisk until well blended. Be sure to scrape the bottom of the bowl several times to get any stray pockets of flour.
4. Pour the batter into the three prepared cake pans and bake for 20 to 25 minutes, or until a toothpick inserted in the center comes with only a few wet crumbs clinging to it. Remove the pans to a cooling rack and let cool until just warm, then remove the cakes from the pans and place on cooling racks to finish cooling.
Make the ganache filling:
1. Place the chopped chocolate in a heatproof bowl, making sure that you have chopped the chocolate into very small pieces. Heat the cream to just below a simmer, then pour over the chocolate and let stand for 5 minutes. Stir until smooth, then stir in the butter and whiskey. Let sit until cool.
Make the Irish buttercream:
1. In the bowl of an electric mixer fitted with the paddle attachment, or using a hand mixer, beat the butter until very creamy. Add the powdered sugar, a little at a time, until fully incorporated, then add the Bailey’s, a tablespoon at a time. Beat until quite creamy. The frosting should be stiff, but still spreadable. If you need to thin it a bit with more Bailey’s or milk/cream, do so.
Make the ganache glaze:
1. Follow the same instructions above for the ganache filling, omitting the final step of adding the butter and whiskey.
Assemble the cake:
1. Using a sharp serrated knife, level the cakes and slice each cake into two layers (you should have six layers total). Make sure you are working the following steps on a cardboard cake circle or another mobile surface so you can move the cake once finished.
2. Place one layer of cake on the cake circle and spread with a layer of the cooled ganache filling, then top with another cake layer. Spread that layer with buttercream. Keep alternating the cake layers with ganache filling and buttercream until all the cake layers are used.
3. Use the remainder of the buttercream to frost the cake. It’s helpful to first apply a very thin layer of buttercream to the cake (called a crumb coat) and then refrigerate the cake for 15 or 20 minutes, then apply the bulk of the buttercream. This helps seal in the crumbs so you don’t have an abundance of cake crumbs strewn throughout your pretty ivory frosting.
4. If you are using the ganache glaze, place the cake in the refrigerator for an hour or so, making sure the cake is quite cold before proceeding. Remove the cake from the refrigerator. Starting in the center of the cake, pour the ganache glaze onto the center of the cake. Let the ganache run to the edges of the cake, then drizzle down the sides. It should set fairly quickly in an attractive mid-drizzle pattern down the sides of the cake.
5. Refrigerate the cake until ready to serve. Serve in thin slices.