Whisk together the flour, cornstarch, baking powder, baking soda, salt and sugar in a medium bowl. In another bowl, whisk together the milk, buttermilk, oil, egg and vanilla. Add the dry ingredients into the bowl with the wet ingredients and whisk until just combined and a few lumps remain. Set aside to rest for 30 minutes.

Preheat a waffle iron. Pour in batter and cook according to the manufacturer’s instructions, until the waffles are crisp and golden. Serve immediately with your choice of toppings.