Put the flour, margarine, sugar, egg, vanilla sugar and baking powder in a bowl and knead into a dough. Roll out 2/3 of the dough and place in a greased springform pan (28 cm diameter).
Peel the apples, cut into thin wedges and cover the dough thickly. Roll out the remaining third of the dough and place on the apples and brush with egg.
Bake for about 50 minutes at 175 ° C. First 15 min with lower heat, the rest of the time with lower and upper heat. Check with the swab sample before removing!