In a medium size mixing bowl, add self-rising yellow corn meal mix, all-purpose flour, granulated sugar, baking powder, baking soda, salt, Old Bay seasoning, egg, diced onions, and a single cup of buttermilk. 
Stir to combine and allow the mixture to rest for 10-minutes.
In a stock pot, heat 4-5 cups of canola, peanut, or vegetable oil to 375 degrees; use a candy thermometer to determine the temperature of the oil.
When the oil is hot, gently drop in a heaping tablespoon of the batter into the hot oil, the raw batter will sink to the bottom of the oil, and when finished cooking, the hushpuppy will rise to the top of the oil. 
Using a slotted spoon, transfer the cooked hush puppies to a plate lined with paper towels to absorb the excess oil.