01 - Preheat the air fryer to 400°F for 3 minutes.
02 - Separate the onion slices into individual rings and set aside.
03 - In three shallow bowls, place the following: Bowl 1 with flour, cornstarch, garlic powder, smoked paprika, salt, and black pepper; Bowl 2 with whisked eggs and buttermilk; Bowl 3 with panko breadcrumbs.
04 - Dredge each onion ring first in the flour mixture, then dip into the egg mixture, and finally coat thoroughly with panko breadcrumbs, pressing gently to adhere.
05 - Place the coated onion rings in a single layer inside the air fryer basket and lightly spray with olive oil.
06 - Cook the onion rings at 400°F for 10 to 12 minutes, flipping halfway through and re-spraying with olive oil if needed until golden and crispy.
07 - While the onion rings are cooking, combine all spicy burger sauce ingredients in a small bowl, mix well, and adjust seasoning to taste.
08 - Serve the hot, crispy onion rings accompanied by the spicy burger sauce for dipping.