For the apple-nut strudel, peel and finely grate the apples. Mix with sugar, vanilla sugar, cinnamon, lemon juice, rum and salt. Roll out the puff pastry on a baking sheet and spread the crumbs and the grated apples on it.
Sprinkle with hazelnuts and raisins. Fold the strudel, brush the edges with egg and close. Turn it over so that the closure is at the bottom.
Now decorate the strudel and brush with beaten egg, possibly sprinkle with sliced almonds. Prick the strudel several times with a fork so that the strudel does not burst.
Put into the preheated oven and bake for about 20-25 minutes at 180° C.