Whisk together flour, sugar, baking powder and salt.
Add milk, vanilla essence and eggs. Whisk until combined.
Add melted butter and whisk until lump-free and smooth.
Optional but recommended: Refrigerate the batter for at least 2 hours or overnight. This makes the waffles softer inside and develops more flavour.
Preheat your waffle iron.
Ladle in batter just until the top of the grids are covered — do not overfill or batter will leak out the sides.
Cook until golden and crispy — about 3–4 minutes for a quality waffle maker, up to 6 minutes for standard models.
Serve immediately, or keep warm in a single layer on a rack in a low oven.
Makes 4–5 large waffles or 6–7 with a standard waffle maker. Leftover batter keeps in the fridge for 2 days.