Begin by heating vegetable oil in a deep fryer or a large pot to 350°F (175°C). Use a thermometer to ensure the temperature remains consistent.

In a medium bowl, whisk together all-purpose flour, garlic powder, paprika, salt, and black pepper until smooth and well combined.

Pour buttermilk into a separate bowl to create a dipping station for your onion rings.

Take each onion ring and dip it into the buttermilk, letting the excess drip off.

Coat the onion rings in the flour mixture, ensuring they are covered evenly.

Return the coated onion ring back to the buttermilk for a brief soak.

Press each buttermilk-coated onion ring into the panko breadcrumbs, ensuring they are well-coated.

Carefully place the coated onion rings in the hot oil in batches, frying for 2-3 minutes or until golden brown.

Remove the fried onion rings with a slotted spoon and drain on a paper towel-lined plate.