In a mixing bowl, whisk together the flour, cornstarch, baking powder, baking soda and salt. Mix well.
Whisk in milk, vegetable oil, egg, sugar and vanilla.
Let the batter sit for 30 minutes.
Preheat waffle iron.
You can skip the non-stick spray on the waffle iron - the oil in the batter will allow the waffle to release easily. (Vintage cookware would be an exception)
Cook waffles according to your machines instructions.