Combine the sugar and cinnamon together in a bowl; set aside.

Unfold the sheet of puff pastry and place on a floured flat surface.

Using a rolling pin, go over the puff pastry sheet lightly, to remove any indentations from the pastry being folded.

Peel, core and slice the apples.

Toss the apples with the cinnamon/sugar mixture.

Place the apples on top of the sheet of puff pastry, leaving about a one inch border around the edges.

Bake for 15 to 18 minutes in a preheated 415 degree oven.

Let cool before slicing and serving.