Using either a knife or a mandolin, cut the apples into thin slices that are almost see-through. Thinner slices will give you crispier apple chips.
3 medium-sized granny smith apples
Lay the apple slices on the cooling rack, trying not to overlap them. Sprinkle the tops of the apples with the cinnamon and sugar mixture. Flip the apples and sprinkle the backs as well.
Bake for 2 hours, flipping the apples halfway through. When the apples are done baking, they will continue to crisp up while cooling. Leave them to cool in the off oven.
After cooling, store in an airtight bag or container at room temperature.
Notes
You can use any crisp apple variety in this recipe, besides Granny Smith. This includes Pink Lady, McIntosh, and Honeycrisp. If you use a sweeter apple than Granny Smith you can cut back or eliminate the sugar.
You can also make air fryer apple chips, but due to the limited space in air fryers, you'll only be able to do about one medium-sized apple at a time. If you choose to use an air fryer, set it at 300 degrees for 16 minutes and still turn them as you do in this recipe.
You can use a sheet but you will lose the shape a bit. See additional directions in the FAQ.
If you want to add some extra spice, you can also opt to sprinkle your apple chips with nutmeg, ginger, or cardamon.