First, grease a 26 or 28 springform pan and refrigerate.
For the filling, peel, quarter, core and dice the apples.
Mix the quark with the egg, sugar and, if you like, some cinnamon (by hand).
For the dough, mix the flour and baking powder, briefly stir the other ingredients together and add to the flour mixture. Knead everything into a smooth dough. If the dough is too dry / moist, improve it with milk / flour.
Then roll out about 8 mm thick on a lightly floured work surface.
Meanwhile preheat the oven to 180 ° C top / bottom heat.
Now spread the lingonberries evenly on the dough, spread the quark cream on top, sprinkle evenly with apple cubes and chopped walnuts.
Now carefully roll up the dough, being careful not to squeeze the filling out. Then cut the rolling pin with a sharp knife into 2-2.5 cm thick slices and place them in the prepared form.