01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper and lightly spray with olive oil.
02 - Separate onion slices into individual rings, discarding the smallest centers.
03 - Prepare three shallow bowls: Bowl 1 with flour, salt, and black pepper; Bowl 2 with whisked eggs and milk; Bowl 3 with panko breadcrumbs, smoked paprika, and garlic powder.
04 - Dredge each onion ring in flour mixture, dip into egg mixture, then coat thoroughly with panko mixture. Press gently to ensure crumbs adhere.
05 - Place coated rings in a single layer on the prepared baking sheet. Lightly spray the tops with olive oil.
06 - Bake for 12 to 15 minutes until the bottoms are golden brown.
07 - Flip each ring, spray tops with olive oil again, and bake for another 8 to 10 minutes until golden and crispy throughout.
08 - While onion rings bake, whisk together mayonnaise, sour cream, buttermilk, chives, parsley, dill, garlic powder, onion powder, salt, pepper, and lemon juice until smooth. Refrigerate until serving.
09 - Serve hot onion rings immediately with chilled ranch dressing for dipping.