Begin by slicing the onions into 1/4-inch thick rings and separating them into individual rings. Set aside.

In a large bowl, whisk together the flour, baking powder, garlic powder, paprika, salt, and black pepper.

In another bowl, combine the buttermilk and egg, whisking until well blended.

Dip each onion ring first into the flour mixture, coating it thoroughly, then into the buttermilk mixture, and finally into the breadcrumbs, pressing gently to ensure the breadcrumbs adhere well.

Heat about 2 inches of vegetable oil in a deep skillet or pot over medium-high heat until it reaches 350°F.

Carefully add the breaded onion rings to the hot oil in batches, frying for about 2-3 minutes on each side or until golden brown and crispy.

Use a slotted spoon to transfer the fried onion rings to a paper towel-lined plate to drain excess oil.

Serve hot with your favorite dipping sauce, such as ketchup or ranch dressing.