Preheat the air fryer to 350 F. In a small bowl, mix the paprika, ground black pepper, salt, garlic powder, onion powder, cayenne powder, and dried oregano, until well combined.
Place the flour and cornstarch into a large bowl, and whisk in 1 ¼ tablespoons of the spice blend.
Pour the buttermilk into a large bowl, and whisk in the remaining spice blend.
Prepare a dredging station with the buttermilk and flour mixture. Place your chicken thighs on a cooking rack with parchment paper or foil underneath to catch drippings.
Place each chicken thigh into the buttermilk mixture to fully coat. Allow excess buttermilk to drip off the chicken thigh, and then coat each side in the flour mixture. Spray each piece of chicken with cooking spray, so that all of the flour is slightly damp.
Place the prepared chicken into the air fryer basket, working in batches as needed. Air fry for 20 to 25 minutes, flipping when 5 minutes remain. When done, the chicken should be golden brown, and the internal temperature is at least 165 F. Serve warm.