In a large mixing bowl, combine the cornmeal, all-purpose flour, sugar, baking soda, baking powder, Cajun seasoning, salt, and black pepper. Whisk these dry ingredients together until well blended. This step ensures that the flavors are evenly distributed.

In a separate medium-sized bowl, add the milk and vinegar. Let this sit for about 5 minutes. This helps to create a lovely, tangy flavor. Next, whisk in the vegetable oil, along with the egg, and the grated onion until everything is nicely combined.

Now, pour the wet mixture into the bowl with the dry ingredients. Mix gently, just until everything is combined. Don't overmix! You want to keep all that fluffiness in your batter.

In a Dutch oven or a heavy skillet, heat about 1½ inches of oil until it reaches 365 degrees Fahrenheit. This temperature is key to achieving a beautifully crisp exterior.

Using two small spoons, scoop a rounded portion of the batter onto one spoon and gently push it off with the second spoon into the hot oil. Fry the hush puppies for 3 to 5 minutes, turning them occasionally until they are golden brown and floating up to the surface.

Once you’ve reached that glorious golden color, carefully remove the hush puppies from the oil with a slotted spoon. Drain them on paper towels to absorb any excess oil. Serve them hot for the best experience!