Preheat your oven to 225°F (107°C) and line a baking sheet with parchment paper.

Wash and core the apples. Slice them into very thin rounds—ideally 1/8-inch thick—for crispier chips. A mandoline slicer works best, but a sharp knife is fine.

Arrange the slices in a single layer on the baking sheet. Sprinkle lightly with cinnamon.

Bake for 1½ to 2½ hours, flipping halfway through. The longer they bake, the crispier they get.

Once the chips are golden and curled at the edges, remove them from the oven and let them cool. They’ll continue to crisp up as they cool.

Store in an airtight container for up to a week (if they last that long).