Pat the 1½ pounds bone-in, skin-on chicken drumsticks dry with paper towels; keep the skin on for a crispier result.

In a large bowl, add the drumsticks and 1 teaspoon baking powder. Toss until the drumsticks are evenly coated with the baking powder.

On a plate or in a shallow bowl, combine ¼ cup grated Parmesan cheese, ½ teaspoon garlic powder, ½ teaspoon onion powder, ½ teaspoon chili powder, ¼ teaspoon kosher salt, and ⅛ teaspoon ground black pepper. Mix to distribute evenly.

Press the Parmesan-spice mixture onto each drumstick so they are well coated on all sides.

Preheat the air fryer to 380°F if your model recommends preheating. Lightly spray the air fryer basket with cooking spray or oil.

Arrange the coated drumsticks in a single layer in the basket without overlapping; cook in multiple batches if needed.

Air fry at 380°F for 24 minutes, flipping the drumsticks halfway through the 24 minutes (after about 12 minutes).

Increase the air fryer temperature to 400°F and cook for an additional 5–6 minutes, until the exterior is crisp and an instant-read thermometer inserted into the thickest part of a drumstick reads 165°F.

Remove the drumsticks from the air fryer, let rest for a few minutes, then serve.