In a large bowl, combine the buttermilk and hot sauce. Add the chicken pieces and toss to coat completely. Cover and refrigerate for at least 2 hours, or overnight for the best results.
In a separate large shallow bowl, whisk together the flour, garlic powder, onion powder, smoked paprika, salt, black pepper, and cayenne pepper.
Remove one piece of chicken from the buttermilk, letting the excess drip off slightly, then dredge it in the seasoned flour. Press the flour firmly into the chicken, then dip it briefly back into the buttermilk and dredge in the flour a second time for an extra crispy coating. Repeat with all pieces.
Preheat the air fryer to 375°F for 3 minutes.
Spray the air fryer basket with cooking spray. Place the chicken pieces in a single layer with space between each piece, skin side down. Spray the tops generously with cooking spray.
Air fry for 12 minutes, then carefully flip each piece and spray the other side with cooking spray. Continue cooking for 10 to 14 minutes more until the chicken is deep golden and the internal temperature reaches 165°F.
Remove the chicken from the air fryer and let it rest on a wire rack for 5 minutes so the coating stays crispy. Serve immediately.