Preheat oven to 200 degrees.
Using a knife, or a mandolin, holding the apple with the stem on the side, slice apple into thin, round chips.You can also use other fruits such as pears.
Place parchment paper onto baking sheet. Lay the apple slices onto the baking sheets. Sprinkle slices with cinnamon.
Bake for about 1 hour, then flip over the apple slices. Continue baking for another 1-2 hours. Flip occasionally, and bake until the slices are no longer moist.
Allow to cool for 10-20 minutes. Keep in an air-tight container to store.