Preheat the oven to 350°F. Lightly grease two (8-inch) round cake pans with butter or baking spray and line the bottom of each pan with parchment paper. (I highly recommend using soaked cake strips for baking flat cake layers.)

In a large mixing bowl, whisk together the flour, sugar, baking soda, baking powder, and salt. Set aside.

Place the cocoa powder and espresso powder in a medium bowl. While whisking, slowly pour in the boiling water, and whisk until the cocoa powder is fully dissolved. Whisk in the milk, sour cream, and oil until combined, then add the eggs and vanilla, and whisk well combined.

Pour the cocoa mixture into the flour and whisk together until all of the dry ingredients have been incorporated and the batter is smooth. (The batter will be runny.) Divide the batter between the prepared cake pans.

Bake for 30 to 35 minutes or until the springs back when gently pressed and the sides of the cake start to pull away from the pan. Let the cakes cool in the pans on a wire rack for 20 minutes. Carefully invert the cake layers onto the wire rack, place parchment paper-side down, and let cool completely.

While the cakes are cooling, place the cherries, sugar, and kirsch in a medium bowl and stir to combine. Cover and let cherries macerate for 30 minutes to 1 hour, stirring occasionally. Drain off the syrup that has collected in the bottom of the bowl. Add enough cold water or more kirsch to the syrup to make ⅔ cup (160ml), if needed. Set aside.

Place the cold cream and powdered sugar in the bowl of a stand mixer with the whisk attachment (or a large mixing bowl if using an electric hand mixer), and beat on medium speed until the cream starts to thicken, about 1 minute. Then increase the speed to medium-high, and continue beating until soft peaks form, about 2 minutes. Drizzle in the kirsch and beat just until the cream forms stiff peaks, 30 seconds to 1 minute. Reserve 1 cup of the whipped cream in a piping bag fitted with a closed start tip and place it in the fridge.

Remove the parchment paper from the cooled cake layers. Cut each cake layer in half horizontally, so you have 4 thinner layers. (Each will have a top half and bottom half.) Reserve one bottom half to use as the final, top layer of the cake so you have a smooth, even top. Place the other bottom layer cut-side up on a serving plate. Brush 3 to 4 tablespoons of the reserved cherry syrup onto the top of the cake. Spread about ¾ cup of whipped cream on top, smoothing it out to the edges, then arrange about a third of the macerate cherries on top of the whipped cream in an even layer. (I like to put them cut side down into the cream to avoid big gaps between the layers.)

Place another cake layer on top, cut-side up, and gently press it down, just enough until it’s even. Repeat by brushing with more syrup and adding whipped cream and cherries. Add another cake layer and top with syrup, whipped cream and cherries as before. Place the reserved bottom layer cut-side down so the smooth side is on top, and press down gently until the top is even.

Spread the remaining whipped cream all over the top and sides of the cake in a smooth, even layer. Press chocolate curls onto the sides and sprinkle them on top of the cake, if desired. If you want to add a ganache drip, chill the cake for 30 minutes. Then, pipe the runny ganache around the top edge of the cake, letting it drip down the sides.

Pipe the reserved whipped cream on top and garnish with additional fresh cherries. Keep the cake refrigerated until you are ready to serve.