01 - In a large mixing bowl, thoroughly whisk together the cornmeal, flour, baking powder, baking soda, kosher salt, granulated sugar, cayenne pepper, and black pepper.
02 - In a separate bowl, beat together the buttermilk, egg, and melted unsalted butter until the mixture is well combined.
03 - Pour the wet ingredients into the dry ingredient mixture and stir gently with a spatula just until the components are combined. Take care not to overmix the batter.
04 - Fold in the finely diced yellow onion, chopped chives or green onions, and the finely chopped jalapeño (if using). Allow the batter to rest undisturbed for 5 minutes.
05 - In a heavy-bottomed pot or Dutch oven, heat approximately 2 inches of vegetable oil to a temperature of 350°F (175°C).
06 - Using two spoons or a small ice cream scoop, carefully drop tablespoon-sized portions of the batter into the hot oil. Fry the hush puppies in batches to avoid overcrowding the pot.
07 - Fry the hush puppies for 2 to 3 minutes per side, turning them as needed, until they achieve a deep golden brown color and a crisp exterior.
08 - Remove the fried hush puppies from the oil using a slotted spoon and transfer them to a plate lined with paper towels to drain any excess oil. Serve immediately while hot.