Prepare Dry Ingredients: In a mixing bowl, whisk together cornmeal, flour, baking powder, baking soda, salt, and sugar until well combined.
Mix Wet Ingredients: In another bowl, beat the egg and whisk in buttermilk and melted butter until smooth.
Combine Batter: Gradually pour the wet ingredients into the dry mixture, stirring until just combined. Fold in the minced onion. The batter should be thick but scoopable.
Heat Oil: In a deep frying pan or Dutch oven, heat oil to 350°F (175°C). Use a thermometer if possible for accuracy.
Fry Hush Puppies: Drop spoonfuls of batter (about 1 tablespoon each) into the hot oil. Fry in batches for 2–3 minutes per side, until golden brown and crispy.
Drain and Serve: Remove with a slotted spoon and place on paper towels to drain excess oil. Serve hot with honey butter, tartar sauce, or your favorite dipping sauce.