Cherry Crumble Cake (Kirsch-Streusel-Kuchen)

Steps

1. Cream the butter with the sugar and egg until smooth.
2. Mix the flour with the baking powder, sift over the butter mixture, and knead into a smooth dough by hand or with a mixer's dough hooks.
3. Grease a springform pan or line with parchment paper. Press two-thirds of the dough into the pan, pulling it up about 2-3 cm along the sides.
4. Drain the cherries, reserving the juice. Mix 2 tbsp sugar and the pudding powder with 6 tbsp of the reserved cherry juice.
5. Top up the remaining cherry juice with water to reach 440 ml, then bring to a boil in a pot.
6. Stir in the pudding powder mixture and cook, stirring vigorously, for about 1 minute until thickened.
7. Remove from heat, stir in the cherries, and let cool slightly. Spread the cherry mixture over the dough in the pan.
8. For the crumble, knead the remaining third of the dough with 3 tbsp flour, the vanilla sugar, and optional cinnamon. Crumble this mixture over the cherries.
9. Bake in a preheated oven at 180°C (fan) for about 45 minutes, until the crumble topping is golden.
10. Let the cake cool slightly, dust with powdered sugar, and serve with a dollop of whipped cream.