Center the oven rack and preheat the oven to 400 F (200 C).
On a silicone mat, roll out the pastry into a rectangle.
Cut the 4 edges of the pastry 1/2″ (1 cm) wide.
Dampen the edges of the pastry rectangle and reposition the strips on the edges of the rectangle.

Arrange the apple slices aesthetically, then sprinkle with vanilla sugar

Bake for 25 minutes or until the pastry is puffed and golden brown.
Remove from the oven and brush the apples with melted quince jelly.