Wash the lemons, grate them dry and grate the peel. Use the rest of the lemon for other purposes. Cream 250 g butter, 200 g sugar, salt and vanilla sugar with the whisk of the hand mixer.
Stir in the eggs one by one. Stir in about half of the lemon peel. Mix 300 g flour, baking powder and poppy seeds and stir in alternately with the yoghurt. Pour the dough into a greased springform pan (26 cm Ø), dust with flour.
First knead 100 g sugar, 100 g butter, 200 g flour and remaining lemon zest with the dough hooks of the hand mixer, then with your hands to form crumbles. Pour the cherries into a sieve and drain well.
Spread the cherries on the dough. Put crumbles on top. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 55 minutes. Take out and let cool down. Dust with icing sugar.