1 Drain the juice from the sour cherries in a sieve over a bowl (save the juice for another use).
2 Rinse lemon in hot water, wipe dry and finely grate peel.
3 Beat eggs with 1 pinch of salt, sugar and 1 tablespoon of hot water until light and creamy, about 3 minutes.
4 Add lemon peel, vanilla sugar and cinnamon to the eggs and stir. Add the ricotta, quark and semolina. Stir briefly with a hand mixer and fold in the cherries.
5 Line a 20 cm (approximately 8-inch) diameter springform pan with parchment paper. Fill pan with batter and smooth surface. Bake the cake in a preheated oven on the middle rack at 180°C (fan 160°C, gas mark 2-3) (approximately 350°F/convection 325°F) for about 45 minutes.
6 Remove cake from oven and cool on a wire rack for 10 minutes. Remove springform edge and let cake cool completely. Before serving, place powdered sugar in a tea strainer and sprinkle over the cake.