Preheat your air fryer to 380°F (193°C).
Prep the apple rings: Peel, core, then cut the apples into rings. Use a corer and then slice to shape.
In a medium-sized bowl, mix together the flour, sugar, and cinnamon. Set aside.
In a shallow dish, beat the egg and then mix in the milk. Pour this mixture into the flour mixture and stir to combine.
In another shallow dish, mix together the sugar and cinnamon for the topping.
Dip each apple ring into the batter, allowing the excess batter to drip off. Place the battered rings on a sheet of parchment paper.
Next, dip each ring into the cinnamon sugar mixture, ensuring they are evenly coated.
Spray the bottom of the air fryer basket with cooking spray, making sure it is thoroughly coated.
Place the apple rings in the air fryer basket, ensuring they are separated and not touching. You will need to cook them in batches.
Lightly spray the apple rings with cooking oil, then air fry them for 5 minutes.
Remove the basket, flip the apple rings over, and air fry for an additional 2-3 minutes or until the apple rings are golden and crispy.
Once finished, remove the apple rings from the basket and allow them to cool for about 10 minutes.
Serve with caramel sauce for dipping, if desired.
Store any leftover Air Fryer Cinnamon Apple Rings in an airtight container for up to 2 days.