1. For the cookie layer, mix all ingredients until they form a nice homogeneous dough. Warp in plastic wrap and chill for about 60 minutes.
2. Use a 12" spring form and press enough of the dough to cover the bottom with a thin layer (maybe 4-5mm) and use a fork to punch holes all over it to prevent it from bubbling up.
   
3. Bake at 375° F in a preheated oven for 10 - 12 minutes until golden.
4. Take out and cool on a cooling rack.
5. Separate the eggs and in an electric stand mixer, whip the egg whites with the cream of tartar and the salt until stiff peaks form. Put into the fridge until needed
6. In the bowl of a electric mixer with the whisk attachment, add the egg yolks, sugar, instant coffee and drizzle in the hot water while the machine is running.
7. Beat on high for about 10 minutes until the mixture is pale and very fluffy.
8. Mix the dry ingredients: flour, cornstarch, cocoa powder, and baking powder and sift over the egg yolk mixture. Fold in gently until well combined.
9. Fold in the egg whites in two rounds and fill into a prepared spring form (do not grease the sides).
10. Bake in a 375° F oven for 30 - 45 minutes until a wooden stick inserted comes out clean.
11. Let rest in the form for 15 minutes, then take it out and put it on a cooling rack to cool completely.
12. For the cherry filling, drain the cherries form the jar and save 2 cups of the juice. Mix sugar and cornstarch with some of that juice and bring the rest to a boil.
13. Once the juice boils, add cornstarch and cook for another 2 minutes. Pour over the cherries, stir in the Kirschwasser, and set aside until it starts binding.
14. For the cream frosting, add the whipped cream to the electric mixer with the whisk attachment.
15. Start whisking gently and stir in sugar, Kirschwasser, and Sahnesteif*.
    *Sahnesteif is used to stabilize the whipped cream, preventing it from seperating and going back to its liquid form and making it usable for frosting the cake. You might be able to find Sahnesteif as "Whip it" in some grocery stores or specialty bake shops and I've also seen it on Amazon. If you can't find them, there are other ways to stabilize whipped cream, most notably using gelatine.
16. Beat until stiff peaks form but do not over mix.
17. Save about two cups of the cream for decorating in a pastry bag and put into the fridge.
18. To assemble, put the cookie dough layer onto your cake stand
19. Spread cookie layer with the cherry preserves. If you can't get cherry, strawberry works just as well
20. Cut the sponge cake into three layers and add the first layer on top of the cookie layer.
21. Sprinkle the sponge with one third of the Kirschwasser and spread the cherry filling on top.
22. Top with the second layer of sponge cake, sprinkle that with another third of the Kirschwasser and put into the fridge for 30 minutes to let it set. You can see that the top (and actually the bottom layer) broke apart in the process. This isn't a big deal as the whole cake will be frosted with whipped cream and no one will ever no (unless you tell).
23. Spread about 1/3 of the whipped cream onto the second sponge cake layer and top with the last layer. Sprinkle the leftover Kirschwasser over the sponge.
24. Frost the entire cake with the rest of the whipped cream and chill for another 30 minutes. It looks like a lot of cream but you want that creaminess in the cake. By the time, the sides and the top are covered, you'll have a pretty good thickness.
25. Pipe nice swirls for each piece of cake and top with half a maraschino cherry.
26. Sprinkle the chocolate shavings over the top.
27. Serve chilled with a shot of extra good Kirschwasser and a hot cup of coffee!

Guten Appetit!