Warm milk lukewarm, dissolve sugar and yeast in it. Put 200 g flour, 2 tablespoons butter, 1 egg, 1-2 tablespoons stevia and 1 pinch of salt in a bowl. Add yeast milk. Knead first with the dough hooks of the hand mixer, then with your hands until smooth.
Cover the dough and let it rise in a warm place for about 30 minutes.
Mix sour cream, sour cream, 2 eggs, 3 tablespoons stevia, lemon zest, 1 pinch of salt and sauce powder. Knead the yeast dough again and roll out round (approx. 30 cm Ø) on some flour. Put it into a greased Wähen-, Tarte- or Quicheform (ca. 24 cm Ø) and press it lightly.
Spread the mud on the dough. Peel, quarter, core and cut the apple into thin slices. Cover the cake with this and bake in the preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2) for approx. 45 minutes.
Take it out. Heat the jam, spread on the cake. Let it cool down.