In a mixing bowl, whisk together the cornmeal, flour, sugar, baking powder, and salt.
In a separate bowl, beat the egg, then add the buttermilk and vegetable oil. Mix well.
Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix; a few lumps are okay.
Insert wooden skewers or popsicle sticks into each hot dog, leaving enough to use as a handle.
Heat vegetable oil in a deep pot or fryer to 350°F (175°C).
Dip each hot dog into the batter, coating it evenly. Allow any excess batter to drip off.
Carefully place the coated hot dogs into the hot oil and fry until golden brown, about 3-4 minutes. Fry 2-3 corn dogs at a time to avoid overcrowding the pot.
Use a slotted spoon to remove the corn dogs from the oil and place them on a plate lined with paper towels to absorb excess oil.
Repeat the process for the remaining hot dogs.
Allow the corn dogs to cool for a few minutes before serving.