Rinse and pit cherries ( if cherries are from a jar, drain well).
Separate eggs. Whisk egg yolks with milk, custard powder, lemon juice, vanilla sugar, sugar and 1 pinch of salt. Combine with quark and mix well.
Butter springform pan and sprinkle with breadcrumbs.
Beat egg whites until stiff and fold into quark mixture. Spread batter in a pan nad smooth. Spread cherries on top and press them in gently. Bake in preheated oven at 180°C (approximately 350°F) for about 1 1/4 hours (inserted toothpick should come out clean). Remove from the oven and cool slightly. Transfer to a cake plate and cool completely. Dust with powdered sugar and serve.