Whisk together the buttermilk and hot sauce in a bowl and add the catfish. Let soak for 20 minutes.
Remove fish from the buttermilk and lightly pat dry.
Add the breadcrumbs, cornmeal, flour, Cajun seasoning, garlic powder, and salt to a shallow dish, such as a pie plate. Stir to combine.
Dip the catfish fillets in the breading mixture, pressing firmly to adhere the breading to the fish.
Spritz air fryer basket with oil spray and add the fish in a single layer without crowding the basket. You may need to work in batches. Spritz fish liberally with oil spray.
Air fry at 400 degrees for 10 minutes. Flip and continue cooking for 10 minutes more or until the fish is crispy and easily flakes with a fork.
Notes
Flipping the fish can be a bit tricky. You’ll want a thin, flexible spatula to make the job easier. Alternately, you can skip flipping the fish, but the underside won’t be quite as crispy. If working in batches, keep cooked fish in a warm oven (180 degrees) until all the fish is cooked and ready to serve.