Add apples, lemon or orange juice, cinnamon, and raw sugar, and lightly fry/steam (approximately 5 minutes, depending on quantity) until the escaping liquid evaporates. Remove the pan from the heat and stir in the grated hazelnuts, almonds, and sultanas. Preheat the oven to 180 °C. Place a sheet of strudel pastry on a clean kitchen towel and place 2 tbsp filling on the bottom edge. Fold in the side edges and carefully roll up the sheet, starting at the filling. Place seam side down on a baking tray and brush with oil. Do the same with the other sheets until the filling is used up.