Wash and dry the apple thoroughly.
Slice the apple evenly into 1/8-inch thick rounds using a sharp knife or mandoline.
Carefully remove any seeds while keeping the slices intact.
In a small bowl, combine the sugar and ground cinnamon.
Sprinkle the cinnamon sugar evenly over both sides of each apple slice.
Lightly coat the air fryer basket with cooking spray.
Arrange the apple slices in a single layer, avoiding too much overlap.
Cook the Air Fryer Cinnamon Apple Chips at 300°F (150°C) for 15 minutes.
Flip or toss the apple slices every 5 minutes, checking more frequently during the last few minutes to prevent burning.
Remove the apple chips when they are lightly golden and nearly crisp.
Transfer them to a cooling rack and allow them to cool completely. They will become crispier as they cool.
Serve immediately or store for later.