Chop the apples into small pieces (about 3/4-inch pieces) and add them to a mixing bowl.
Add the brown sugar and spices and toss everything together very well until combined. Set it aside.
In a separate bowl, combine the sugar, cinnamon, oats, flour and salt for the topping.
Cut the cold butter into small pieces and add them to the bowl with the topping ingredients. Use your hands or a pastry cutter to crumble the butter into the dry ingredients until the mixture resembles coarse crumbs.
Preheat your air fryer to 350 degrees Fahrenheit (175 degrees Celsius), and spray a small baking dish (7-8 inches square or round) with baking spray.
Add the apples to the baking dish and even out the top.
Add the topping on top of the apples, making sure the top is even.
Add aluminum foil over your baking dish and air fry at 350 degrees Fahrenheit (175 degrees Celsius) for 15 minutes.
After that, remove the aluminum foil, set your air fryer to 400 degrees Fahrenheit (200 degrees Celcius) and air fry for another 2-3 minutes to get some browning and crispiness.
Serve hot with vanilla ice cream, whipped cream or on its own.