Preheat oven to 350°F. Grease two 8 or 9-inch round cake pans and line with parchment rounds, if you have them.
In a large bowl, beat butter and sugar until fluffy, then mix in eggs and vanilla until blended.
In another bowl, whisk together flour, cocoa powders, baking powder, baking soda, and salt.
Mix dry ingredients into the sugar mixture in batches, alternating with the milk.
Pour into prepared pans and bake 30-35 minutes, until cake pulls away from the edges of the pan and a toothpick inserted into the center comes out clean. Let cool in pans 5 minutes before removing to a rack or wrapping tightly in plastic wrap and freezing.
While the cakes are baking, make the filling. Mix together cherries, amaretto, sugar, cornstarch, and Kirsch in a saucepan set over medium heat. Stir and cook until the sugar has dissolved and the cherries are breaking down (help them along with your spatula), and it resembles pie filling or jam, about 10 minutes. Cool in the refrigerator.
When ready to assemble the cake, whip the cream and slowly add the powdered sugar. Whip until stiff peaks form.
To assemble, place the bottom layer on a stand/plate and spread on about 3/4 of the cherry filling. Top with enough of the whipped cream frosting to cover, using a spatula to spread it to the edges.
Add the second layer of cake, and spread the remaining frosting over the cake. Pour the remaining cherry filling on the top of the cake, and garnish as desired.
Notes
If not using the black cocoa, add 2 tablespoons more regular cocoa powder.