Preheat oven to 450 F. Spray a large baking sheet generously with olive oil.
Slice sweet onion into 1/4″-1/2″ rounds. Separate into rings & discard the small inner core circles.
In a mixing bowl, beat together eggs & buttermilk. Set aside.
Pulse together cornflakes & breadcrumbs in a food processor until fine crumb texture. In a large bowl, mix together cornflake mixture, paprika & garlic salt. Set aside.
Lightly spray the rings with olive oil & dredge in the flour.
Dip rings into the egg mixture and then dredge rings in the cornflake mixture. *If a thicker breading is desired, repeat.
Arrange rings on sprayed baking sheet. Spray top of rings with olive oil. Bake at 450 F for 15-18 min or until golden brown, turning once after 7 min of baking.