Knead the shortcrust ingredients together and leave to cool for 2 hours.
For the filling :
Remove the skin from the apples, core them and cut them into quarters. Heat the butter (but do not let it brown), put it together with the apples in a Reindl form and lightly caramelize it with 120 g sugar. Later, spread evenly in a shallow cake pan and sprinkle with the remaining sugar and vanilla sugar and continue caramelizing in the oven.
Next, roll out the shortcrust pastry and place it on top of the cake pan, poke a few holes in the top of the pastry and bake at a high temperature until the pastry browns.
Cover with aluminum foil and continue baking at a moderate temperature for about 10 more minutes. After removing, place the baking dish on a wet dish rack for 10 minutes, then heat again very briefly and turn out. Cut into pieces at the table.