Cut the apples crosswise into very thin slices (about 1/16"). Lightly tap out any seeds from the center.
Place the apple slices in a mixing bowl and sprinkle with the cinnamon and nutmeg. Toss to coat the slices well.
Place the apple slices in the basket of an air fryer. Set the machine to 200°F and set the timer for 30 minutes.
After 30 minutes, toss the apple slices, and set the timer for 30 more minutes at the same temperature. Toss again. Set the timer for 15 more minutes.
The apple chips will crisp up as they cool. If you're not sure that they are done, take one or two out of the air fryer basket and let them cool. If they're still chewy, return them to the basket and cook for another 10-15 minutes.
To make the dip, Combine the syrup, cocoa powder, and water in a small bowl. Using a fork, whisk well until the mixture is smooth. Stir in the tahini and whisk until smooth.
These are best eaten the same day. If they soften up, cook them in the air fryer at 200 degrees F for 10 minutes or so.