Preheat the oven to 350˚F. Line a baking sheet with parchment paper or use a nonstick baking sheet.
Using a mandolin, carefully slice the apples into ⅛ inch slices.
Arrange the apple slices in a single layer on the baking sheet.
Spray the slices with avocado spray and sprinkle with cinnamon.
Bake for 20-30 minutes, flipping halfway, until lightly golden brown.
Let cool to room temperature.