01 - Preheat air fryer to 400°F for 5 minutes to ensure optimal crisping.
02 - Peel onions and slice into 1/2-inch rings. Separate rings and set aside.
03 - Prepare three shallow bowls. Bowl 1: combine flour, garlic powder, smoked paprika, salt, and black pepper. Bowl 2: whisk eggs and milk until blended. Bowl 3: pour in panko breadcrumbs.
04 - Dredge each onion ring in flour mixture, shaking off excess. Dip into egg mixture, allowing excess to drip off. Press firmly into panko breadcrumbs to coat evenly on all sides.
05 - Place coated rings in a single layer in air fryer basket. Work in batches as needed to avoid overcrowding. Lightly spray tops with cooking spray.
06 - Cook at 400°F for 10-12 minutes, flipping halfway through cooking time. Rings are done when golden brown and crispy.
07 - While rings cook, combine mayonnaise, minced chipotle pepper, adobo sauce, lime juice, and salt in small bowl. Mix until smooth and adjust seasoning to taste.
08 - Transfer hot onion rings to serving plate. Serve alongside chipotle mayo for dipping. Best enjoyed immediately while crispy.