Mix flour and baking powder. Add sugar, vanillin sugar, cinnamon, eggs and oil and mix briefly
Coarsely chop the walnuts. Peel, quarter and core apples and then cut them into small cubes. Fold nuts and apple cubes into the dough. Grease a springform pan with a tube bottom insert (26 cm Ø) and sprinkle with breadcrumbs. Fill in the dough and smooth it down
Bake in a hot oven (electric cooker: 175 °C / convection oven: 150 °C / gas: level 2) for about 1 hour. Let it cool down. Dust with icing sugar. Serving with: tastes good whipped cream