Chocolate and cherry are a classic pairing in this traditional cake from the southwest region of Germany, which has inspired our own mile-high rendition.
Preheat the oven to 350°F. Grease two 9" cake round cake pans.
To make the cake: Combine the cocoa, flour, sugar, buttermilk powder, cake enhancer, baking powder, baking soda, and salt.
In a separate bowl, whisk together the water, oil, and vanilla. Gradually beat the wet ingredients into the dry ingredients.
Add the eggs one at a time, beating until well blended. Pour the batter into the prepared pans.
Bake the cakes until a tester comes out clean, about 25 to 30 minutes. Cool the cakes in the pans for 15 minutes, then turn them out onto a rack to cool completely.
To make the filling: If you're using a jar of sour cherry pie filling, strain the cherries from the syrup and reserve both; add the optional Kirsch and cherry flavor to the syrup. If you're using canned pie filling, don't drain; simply stir optional Kirsch and cherry flavor into the pie filling.
Whip the cream, slowly adding the sugar, and then the vanilla. Whip until stiff peaks form.
To assemble the cake: Cut each layer in half horizontally. Place the first layer on a cake board or plate and brush a coating of cherry syrup over the surface. If you're using canned pie filling and don't have cherry syrup, skip this step.
Spread a 1/2" layer of cream onto the cake, and top with 1/3 of the cherries. Repeat with two more layers of cake-syrup-cream-cherries, and top with the final layer of cake.
Use the remaining cream to coat the sides and top of the cake. Decorate with the grated chocolate. Refrigerate the cake until you're ready to serve, up to a few hours; the whipped cream in the filling will gradually deflate, so better to serve this cake sooner rather than later.
