Preheat your oven to 350°F (175°C). Grease and line two 9-inch round cake pans with parchment paper.
In a large mixing bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
Add eggs, milk, oil, and vanilla extract. Mix until well combined.
Gradually add boiling water, mixing until the batter is smooth.
Pour the batter evenly into the prepared pans.
Bake for 30-35 minutes or until a toothpick inserted into the center comes out clean.
Allow the cakes to cool in the pans for 10 minutes, then transfer to a wire rack to cool completely.
In a saucepan, combine cherries and sugar. Cook over medium heat until the cherries release their juices.
In a small bowl, mix cornstarch with a little water to create a smooth paste. Add it to the cherries to thicken the mixture.
Optionally, stir in Kirsch. Allow the cherry filling to cool.
In a chilled bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.
Place one chocolate cake layer on a serving platter.
Spread a layer of whipped cream over the cake, followed by a portion of the cherry filling.
Frost the entire cake with whipped cream and decorate with chocolate shavings and fresh cherries.
Refrigerate the cake for at least 2-3 hours before serving to allow the flavors to meld.