Set the waffle iron to the desired darkness. Preheat the waffle iron.
Place the oil, egg, and milk into the bowl of a stand mixer fitted with a paddle attachment. Mix until the egg is broken up (about 30 seconds).
Add in the flour, cornmeal, salt, and baking powder.
Mix together until smooth (scraping down the sides as needed).
Once the waffle maker is warmed, lightly brush the inside plates with a bit of oil.
Place 1 level cup of batter into the center of the waffle maker. With a heat proof silicone spatula or spoon, spread the batter to cover the waffle plate (leave 1/2" border).
Close the waffle maker and cook until the waffle maker indicator shows that the waffle is cooked.