Preheat Oven to 200 degrees.
Line cookie sheet with parchment paper.
Slice apples thinly.
Pour sugar and cinnamon in a zip lock bag.
Add sliced apples and shake.
Place apple slices in a single layer on the parchment lined cookie sheet.
Bake 200 degrees.
Bake on one side for 1½ hours then flip them over to the other side and bake for another 1 hour.
When the final hour is complete, turn off the oven leaving the apple slices inside overnight.
Store in a ziplock bag.