For the filling, cut the apples and marzipan into small cubes, stir in a saucepan with a little water and cinnamon (the marzipan will dissolve). Stir in the almond slivers and allow to cool.
In the meantime, put the other ingredients for the dough in a bowl and make a quark-oil batter.
Roll out the dough on a floured work surface and cut into 15 cm squares. Place a dollop of the filling on top of each. Brush the sides with a little milk, fold into triangles and press down firmly. Place the bags on a baking sheet lined with parchment paper.
Bake the bags in a preheated oven at 180 ° C until golden brown (approx. 20 to 30 minutes, depending on the oven and the desired browning). Brush with milk again halfway through the baking time.