1. Preheat the oven to 180°C (350°F).
2. Attach the whisk.
3. Place 6 room temperature eggs in the Thermomix bowl.
4. Add 130 grams of granulated sugar to the Thermomix bowl.
5. Add 1 packet of vanilla sugar to the Thermomix bowl.
6. Place the lid with the measuring cup.
7. Heat for 8 min/65°C (150°F)/speed 3.5.
8. Mix for 8 min/speed 3.
9. Remove the whisk.
10. Place 70 grams of flour in a separate container in the Thermomix bowl.
11. Place 80 grams of cornstarch in a separate container in the Thermomix bowl.
12. Add a pinch of salt to a separate container in the Thermomix bowl.
13. Add 30 grams of unsweetened cocoa powder to a separate container in the Thermomix bowl.
14. Add ½ packet of baking powder to a separate container in the Thermomix bowl.
15. Mix everything with a fork, then pour everything into the Thermomix bowl, sifting it with a sieve.
16. Gently mix by lifting the mass with a spatula so that the batter does not deflate.
17. Transfer to a jelly roll pan (40×30 cm or 15×12 inches) and bake in the oven for 14 min at 180°C (350°F). Adjust the baking time according to your oven. If the sponge cake is overcooked, it may break when you try to roll it.
18. Wash and dry the Thermomix bowl.
19. Place the bowl and whisk in the freezer along with the containers of heavy cream and mascarpone.
20. Let it sit for 20 min.
21. Add 2 packets of vanilla sugar to the Thermomix bowl.
22. Add 40 grams of granulated sugar to the Thermomix bowl.
23. Place the lid with the measuring cup.
24. Pulverize for 10 sec/speed 10.
25. Attach the whisk.
26. Add 250 grams of mascarpone to the Thermomix bowl.
27. Add 300 grams of heavy cream to the Thermomix bowl.
28. Place the lid with the measuring cup.
29. Mix for 3 min 30 sec/speed 3, gradually increasing the speed to 4.
30. Transfer to a pastry bag and refrigerate.
31. Place 120 grams of cherries in syrup on your work surface in the Thermomix bowl.
32. Place 20 grams of kirsch (optional) and 60 grams of cherry syrup in a separate container in the Thermomix bowl.
33. Once the sponge cake has cooled, soak it with the kirsch and cherry syrup mixture.
34. Then spread the whipped cream on top, distribute the cherries, and gently roll the cake.
35. Spread a thin layer of cream around the log.
36. Place 10 squares of dark chocolate, cut into shavings with a peeler, on the log in the Thermomix bowl.
37. Add a few cherries on top of the log for decoration :).
38. Refrigerate.