Peel the onions and slice them into ½-inch thick rings. Separate the rings and set aside.

In a shallow bowl, whisk together the flour, cornstarch, baking powder, salt, black pepper, and garlic powder.

In another bowl, beat the eggs and mix in the buttermilk.

In a third bowl, place the panko breadcrumbs.

Dip each onion ring into the flour mixture, shaking off any excess.

Submerge the floured ring into the egg mixture, allowing the excess to drip off.

Finally, coat the ring in panko breadcrumbs, pressing gently to adhere.

Preheat your air fryer to 375°F (190°C) for about 3-5 minutes.

Lightly spray the air fryer basket with cooking spray.

Arrange the onion rings in a single layer in the basket, leaving space between each ring.

Spray the tops of the onion rings lightly with cooking spray to help them crisp up.

Air fry at 375°F (190°C) for 8-10 minutes, flipping halfway through, until golden brown and crispy.

Remove the onion rings from the air fryer and let them cool slightly. Serve warm with your favorite dipping sauce.