01 -
Preheat the oven to 350°F (180°C). Line two 8-inch round cake pans with parchment paper on the bottoms and set them aside.
02 -
In a stand mixing bowl, combine the flour, granulated sugar, brown sugar, baking soda, baking powder, salt, and espresso powder. Add in the cubed butter and mix for 3 minutes on low until the mixture resembles coarse sand.
03 -
Add the sour cream and oil to the bowl. Mix on low speed for exactly one minute. The mixture should become a very thick paste.
04 -
In a bowl with a spout, whisk together the eggs, milk, and vanilla. Separately, mix the hot coffee and cocoa powder in another bowl until smooth.
05 -
With the mixer on low, slowly add the egg mixture to the batter and mix until just combined. Follow by slowly adding the coffee-cocoa mixture, mixing just until combined. Scrape down the bowl to ensure no streaks of batter remain.
06 -
Evenly distribute the batter into the prepared cake pans, approximately 725 grams in each. Bake for 33-36 minutes or until a toothpick inserted in the center comes out clean with a few moist crumbs.
07 -
Cool the cakes in the pans on a wire rack for 20 minutes, then run an offset spatula around the edges. Flip the cakes out of the pans and continue cooling completely on the rack.
08 -
In a stand mixer, cream the butter, cocoa powder, and powdered sugar on low speed until combined. Increase the speed to medium-high and mix for 3 minutes until fluffy. Add the cooled coffee, cream, vanilla, and salt, and continue mixing until light and fluffy.
09 -
In a small pot, whisk together the cocoa powder, sugar, coffee, water, vanilla, and salt. Cook over medium heat until it boils, then reduce to low and simmer for 2-3 minutes until slightly thickened. Transfer to a bowl to cool.
10 -
Trim the domes off the cake layers with a serrated knife. Place the first layer on a cake stand and drizzle with 1 tablespoon of chocolate coffee syrup. Spread 1/4 cup of buttercream evenly over the cake. Repeat with the remaining layers, flipping the last layer upside down for a flat surface.
11 -
Apply a thin, even layer of buttercream to the entire cake. Drizzle with more chocolate coffee syrup and decorate as desired (e.g., coffee truffles or shaved chocolate).