What you need:
4 apples
2 Tablespoons cinnamon
How you do it:
Preheat oven to 200 degrees Fahrenheit
Core your apples. (You can peel them too if you would like, but do not have to)
Cut your apples into very thin slices (the thinner the better, using a mandoline for this works great if you have one)
Line 2 baking sheets with parchment paper
Place your apples in a single layer on top of the parchment paper
Sprinkle the apples with cinnamon
Place in the oven and bake for at least 2 hours. It may take longer depending on the thickness of your apples, I recommend checking them every 30 minutes to an hour.