5 medium Granny Smith apples, sliced thinly
Slice apples in uniform think slices using a mandolin. Place cinnamon and sugar in a gallon ziplock bag. Add apples to ziplock bag with cinnamon and sugar mixture and shake until all apple slices are covered. Place on a parchment or silicone baking mat lined baking sheet. Slices can touch each other, but try not to overlap them as they will not crisp evenly. Fit as many apples on a sheet as you can. They do not have to lay perfectly flat.
Bake apples at 170 for 6-8 hours, until dry and slightly shriveled, and curled up around edges. Turn off oven and leave door shut until completely cooled. Remove apples from baking sheet and store in an airtight container.