Chocolate Buttermilk Cake

1. Preheat the oven to 350F(175C). Grease (2) 6” baking pans and line the base of each pan with 6” parchment paper circle cutouts.
2. Using a fine mesh strainer, sift the flour, cocoa powder, baking powder, baking soda, and salt into a large mixing bowl. Alternatively, the flour, cocoa powder, baking powder, baking soda and salt may be whisked together in a large mixing bowl.
3. In a separate large mixing bowl, whisk together the oil, sugar, eggs and vanilla extract. Next, whisk the buttermilk into the wet batter to combine.
4. Pour the wet batter into the bowl with the dry ingredients. Using a hand mixer at low speed or wire whisk, mix the wet batter into the dry ingredients followed by the coffee/espresso just until you have a smooth cake batter, about 1-2 minutes. Take cake to not overmix the cake batter.
5. Equally divide the batter into the prepared baking pans and bake for 30-35 minutes or until a toothpick inserted into the center of one of the cakes comes out clean.
6. Cool chocolate cakes in the pans for 10-15 minutes before transferring to a cooling rack to cool completely to room temperature.

Salted Chocolate Buttercream

1. In a stand mixer fitted with paddle attachment or in a large mixing bowl with a hand mixer, cream the butter at medium high speed until it is smooth and fluffy in appearance, about 2-3 minutes.
2. Reduce the mixer speed to low and mix in the confectioners’ sugar and cocoa powder into creamed butter. Gradually increase the mixer speed back to medium.
3. Once all the sugar and cocoa powder have been incorporated into the butter, mix in 1 tablespoon of the heavy whipping cream and vanilla extract into the buttercream.
4. If buttercream appears too thick, mix in additional cream 1/2 tablespoon at a time until the desired consistency (thick but spreadable) is reached. If buttercream appears to be too soft, mix in additional confectioners’ sugar 1/4 cup at a time until a thick but spreadable consistency is reached.
5. Increase mixer speed to medium high and mix chocolate buttercream for an additional 30-60 seconds. The resulting buttercream should be smooth and fluffy in appearance.

Assembly 

1. Level cooled chocolate cakes with a serrated knife or cake leveler. This will allow cakes to be evenly stacked and assembled.
2. Position the first cake layer faced up on a cake stand or serving plate of choice. Spoon about a heaping 1/2 cup of the buttercream onto the cake and spread into an even layer using an offset (angled) spatula.
3. Place the final cake layer faced down on top of the first layer. Using an offset spatula, apply a thin layer of the buttercream over the entire surface of the cake and smooth out using an offset spatula (top of cake) and bench scraper (sides of the cake).
4. Place the cake in the refrigerator for at least 30-60 minutes to allow the crumb coat to firm up. Apply a thick layer of the remaining buttercream onto the chilled cake and smooth out in a similar fashion like the crumb coat.
5. Run the back of an offset spatula along the top surface of the cake in a circular motion starting at the border and ending in the center of the cake for spiral design.
6. Sprinkle the top of the cake with flaky sea salt (optional) before serving.