Preheat the oven to 225°F (110°C). A low temperature helps the apples dry out slowly and turn crisp without burning.

Prepare your pans. Line two large baking sheets with parchment paper or silicone baking mats. Lightly mist with nonstick spray if needed.

Wash and core the apples. You can leave the peel on for extra fiber and color. Use an apple corer if you have one. If not, simply slice around the core and discard the center.

Slice thinly and evenly. Aim for 1/16–1/8 inch (about 1.5–3 mm). A mandoline makes this quick and consistent. Even slices dry at the same rate and deliver the best crunch.

Optional: Toss with lemon juice. If you’re slicing ahead or prefer a brighter flavor, lightly toss the slices with lemon juice to slow browning.

Arrange on the pans. Lay the apple slices in a single layer with no overlap. Crowding causes steaming instead of drying.

Season lightly. Sprinkle with cinnamon. If desired, dust with a little sugar for extra sweetness. A light, even coating is best.

Bake low and slow. Place the sheets in the oven and bake for 1 hour. Rotate the pans, then bake another 45–75 minutes, checking every 15 minutes near the end. Total time is usually 2–2.5 hours.

Test for doneness. Chips should feel dry and slightly firm. They’ll crisp more as they cool. If they still feel soft or bendy, keep baking in short increments.

Cool on the pans. Turn off the oven, crack the door, and let the chips cool for 15–30 minutes. This step helps lock in the crunch.

Serve or store. Enjoy right away, or transfer completely cooled chips to an airtight container.