In a medium bowl, combine the flour, cornflour, baking powder, baking soda, salt, sugar and any spice you may be using. Whisk to mix well. Add the milk, buttermilk, oil, egg and vanilla extract. Whisk to blend well so that few (if any) lumps remain. Set aside to rest for 30 minutes. Preheat your waffle iron. We usually leave ours at its maximum setting. It’s useful to grease the waffle maker just for the first waffle. If you’re adding fruit to the batter, do so at this point, just before you use the batter. Gently stir to ensure that you get some fruit into each portion of batter. Pour the appropriate amount of batter into the hot waffle iron (ours comes with a measuring cup). Cook until golden and crisp.