In a large mixing bowl, whisk together flour, cornstarch, salt, baking powder, and baking soda.
In a separate bowl combine buttermilk, oil, egg, sugar, and vanilla. Mix well and then pour into the dry mixture, stirring well to combine.
Let the batter rest for 30 minutes.
When ready, preheat the waffle iron. Pour batter onto heated waffle iron and heat according to machine directions. Waffles are done when they are crispy on the edges and golden brown.
Dust with confectioners' sugar. Serve with butter and maple syrup.