Slice the apple thinly.
Mix flour, butter, sugar, and salt to make dough.
Let the dough rest in the refrigerator for 30 minutes.
Roll out the dough and place it into a tart pan.
Arrange the sliced apples on top of the dough.
Sprinkle sugar and cinnamon powder over the apples.
Bake in a preheated oven at 180°C for 30-35 minutes.