1Pat the chicken drumsticks dry with paper towels, then soak them in a cup of whole milk for at least 30 minutes (preferably overnight) to make them more tender.
2In a large bowl, thoroughly mix the Parmesan, arrowroot flour, cornstarch, turmeric, paprika, cayenne, garlic powder, onion powder, black pepper, brown sugar, salt, and dried thyme.
3Remove the drumsticks from the milk and, using tongs, roll each piece in the spice mixture until evenly coated.
4Place the drumsticks in the air fryer basket, leaving space between them for even cooking.
5Lightly spray the tops with olive oil spray.
6Cook at 200°C (400°F) for 10 minutes. Turn the drumsticks, spray again, and cook for another 10 minutes.
7Turn once more, spray, and cook for a final 5 minutes.
8Check the internal temperature – it should reach 74°C (165°F). Serve immediately, hot.