Cut the onion into bite-sized pieces, separating the layers gently.
In a large bowl, whisk together the flour, paprika, garlic powder, onion powder, salt, black pepper, and cayenne pepper.
In another bowl, pour the buttermilk.
Place the breadcrumbs in a third bowl.
Dip each onion piece into the buttermilk, allowing excess to drip off, then coat it in the flour mixture, shaking off any excess.
Dip it back into the buttermilk and then coat it with breadcrumbs, pressing gently to adhere.
In a deep skillet or fryer, heat oil to 350°F.
Carefully add the coated onion pieces in batches, frying until golden brown and crispy, about 3-4 minutes.
Remove with a slotted spoon and drain on paper towels.
Serve warm with your favorite dipping sauce.