Grind the nuts. Mix flour and baking powder. Add sugar, vanillin sugar, cinnamon, eggs and oil and work into a smooth dough with the whisk of the hand mixer. Stir in nuts.
Wash, peel and quarter the apples and cut out the cores. Roughly dice the apple quarters and fold into the dough. Fill the dough into a greased springform pan (26 cm Ø) with breadcrumbs and a tube bottom insert.
Bake in the preheated oven (electric oven: 175 °C/ gas: level 2) for about 1 hour. Take the cake out of the oven and let it cool down a little on a grid. Remove from the mould, turn out and dust with icing sugar.