Preheat your waffle iron.

Whisk flour, sugar, baking powder, bicarb and salt in a large bowl.

In another bowl, whisk buttermilk, melted butter, egg yolks and vanilla.

Pour wet into dry. Whisk until just combined — lumps are fine. Don't overmix.

Beat egg whites to stiff peaks. Fold gently into the batter in 3 additions.

Ladle batter into the hot iron. Cook 4-5 minutes per waffle, or until almost no steam rises.

Serve immediately with butter and maple syrup. Or hold in a 90°C oven on a wire rack while you cook the rest.