Mix flour, butter, and sugar to make a dough.
Let the dough rest in the refrigerator for 30 minutes.
Thinly slice apples and mix with sugar and cinnamon for the filling.
Roll out the dough and place it in the pan.
Place the filling on top of the dough.
Cover with the top layer of dough and seal the edges.
Brush the surface with egg wash.
Bake in a preheated oven at 180°C for 40 minutes.