Cut onion into 1/4 inch rings. Carefully separate the rings.
In a medium bowl add flour, paprika, cayenne pepper, and baking powder and whisk until combined.
In a small bowl whisk egg and milk and set aside.
In a separate bowl add Panko bread crumbs, bread crumbs, Parmesan, and mix.
Dip the onion slices into the flour mixture until they are all coated. Then dip it into the egg mixture. Then into the breadcrumb mixture, back into the egg mixture, and again into the breadcrumb mixture. Then lay it on a baking sheet. Repeat until done.
Add about 2 inches of oil to a pot and heat the oil to 325 degrees in a large heavy pot or deep fryer. It should be at least 2-3 inches deep.
Fry for 2-3 minutes or until golden, turning about halfway through.
Place a cooling rack on a baking sheet. Place the fried onion rings on the cooling rack to drain.
Serve with your favorite sauce.
Sriracha Sauce
In a small bowl mix mayo, sugar, and sriracha.
Video
Notes
White, yellow, or even sweet onions work well for these.