Preheat oven to 200 degrees.

Using a sharp knife slice apples thinly. Discard seeds. Prepare a baking sheet with parchment paper and arrange apple slices on it without overlapping. Sprinkle cinnamon over apples.

Bake for approximately 1 hour, then flip. Continue baking for 1-2 hours, flipping occasionally, until the apple slices are no longer moist.  Store in airtight container.