In a large bowl, combine the buttermilk, garlic powder, onion powder, paprika, salt, and black pepper. Add the chicken pieces and stir to coat. Cover and marinate in the refrigerator for at least 30 minutes, or up to 2 hours for more flavor.
Preheat the air fryer to 400°F.
In one bowl, place the flour. In another bowl, add the panko breadcrumbs. Remove the chicken from the marinade, allowing excess liquid to drip off. Dredge each piece in flour, shaking off any excess, then dip in the panko breadcrumbs, pressing gently to adhere.
Arrange the coated chicken bites in a single layer in the air fryer basket. Spray lightly with cooking spray.
Cook in the air fryer for 10-12 minutes, shaking the basket halfway through, until the chicken is golden brown and cooked through (internal temperature should reach 165°F).
Serve hot with your favorite dipping sauce.