Soak the sliced onions in buttermilk for at least 30 minutes to tenderize and flavor them.
Preheat your air fryer to 375°F.
In a large bowl, combine the flour, garlic powder, onion powder, paprika, salt, and black pepper.
Remove the onions from the buttermilk, allowing excess liquid to drip off, and coat them in the flour mixture, ensuring they are evenly covered.
Arrange the coated onions in a single layer in the air fryer basket and spray lightly with cooking spray.
Air fry for 10-12 minutes, shaking the basket halfway through, until the onions are golden brown and crispy.
Let them cool slightly before serving.