Place flour, baking powder, salt and icing sugar on the work surface, make a well in the centre and pour in the quark.
Add the milk and oil.
Mix everything with your hands to a smooth dough.
Roll the dough until thin on a floured surface, then use to line the greased quiche tin. Trim off the excess.
Preheat the oven to 190°C (170°C fan, gas 5). Peel and quarter the apples.
Remove the cores.
Cut into thin slices and sprinkle with lemon juice.
Place the apples on the dough, skin side up.
Mix together the eggs, sugar and cream.
Pour over the apples, shake the tin slightly and bake for 30-35 minutes on the middle shelf. Remove from the oven, allow to cool and, if desired, dust with icing sugar before serving.