Start by grabbing a large mixing bowl. Add the flour, sugar, baking powder, baking soda, and salt. Use a whisk to combine these ingredients thoroughly for about thirty seconds. If you see any large lumps of baking soda, break them up with your fingers or the back of a spoon.
In a separate medium-sized bowl, pour in the buttermilk and the melted butter. Crack your eggs into the mixture and add the vanilla extract. Whisk this until the eggs are fully broken down and the butter is incorporated into the liquid
Create a well in the center of your dry ingredients. Pour the liquid mixture into this well. Using a large spatula or a wooden spoon, fold the wet and dry ingredients together. You do not want to use a mixer here. Mix just until you no longer see streaks of dry flour.
Let your bowl of batter sit on the counter for about ten to fifteen minutes while your waffle iron heats up.
Preheat your waffle iron according to the manufacturer’s settings. If your iron has adjustable heat, set it to the medium-high range.
Use a ladle or a measuring cup to pour the batter onto the center of the iron. Do not overfill it, as the batter will expand and drip out the sides. Close the lid gently. Avoid the urge to open the lid too early. Let the waffle cook until the steam stops rising from the sides of the iron.
Transfer the finished waffle to a cooling rack for thirty seconds before serving. Stacking them directly on a plate makes them steam and lose their crispness.
