1. Start by peeling the onions and slicing off the top and root ends. Place the onion cut-side down and make 8-12 vertical cuts around the onion, being careful not to cut all the way through. This will allow the onion petals to separate and “bloom” as they cook.

2. Next, gently spread the onion petals apart and place the onions in a bowl of ice water. Soak for 10-15 minutes to help the petals open up even further. Drain the onions and pat them dry with paper towels.

3. In a shallow bowl, whisk together the flour, paprika, garlic powder, onion powder, salt, and black pepper. In a separate bowl, beat the egg and buttermilk together. In a third bowl, combine the panko breadcrumbs and Parmesan cheese.

4. Working one onion at a time, dredge it in the flour mixture, making sure to coat the petals. Shake off any excess. Dip the onion in the egg mixture, allowing the excess to drip off. Finally, coat the onion in the panko-Parmesan mixture, pressing gently to help it adhere.

5. Preheat your air fryer to 375°F. Lightly spray the air fryer basket with cooking spray. Carefully place the coated onions in the basket, being careful not to overcrowd. Generously spray the tops of the onions with cooking spray.

6. Air fry the onions for 15-18 minutes, flipping and spraying with additional cooking spray halfway through, until they are golden brown and crispy. Adjust the cooking time as needed based on your specific air fryer model.