Pat the chicken drumsticks very dry with paper towels on all sides. This is crucial for helping the coating adhere and for achieving a crispy finish.
Set up a three-part breading station. In the first shallow dish, place the flour. In the second dish, beat the eggs with the dijon mustard until smooth. In the third dish, combine the panko, parmesan cheese, garlic powder, onion powder, smoked paprika, italian seasoning, salt, and black pepper and stir to mix evenly.
Dredge each drumstick in the flour and shake off the excess. Dip it into the egg mixture, turning to coat completely. Then roll and press it firmly into the panko mixture, making sure the breadcrumbs adhere to every surface. Repeat with all drumsticks.
Preheat the air fryer to 380 degrees F for 3 minutes. Spray the air fryer basket with nonstick cooking spray.
Arrange the coated drumsticks in the basket standing upright or in a single layer, leaving space between each one for air to circulate. Spray the drumsticks generously all over with cooking spray.
Air fry for 12 minutes, then carefully turn each drumstick and give them another light spray of cooking spray. Cook for an additional 10 to 12 minutes until the panko crust is deep golden brown and the internal temperature of the thickest part reaches 175 degrees F.
Let the drumsticks rest on a wire rack for 3 minutes so the coating stays crispy instead of getting soggy from steam. Serve with your favorite dipping sauce such as honey mustard, ranch, or hot sauce.