In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In another bowl, beat the eggs and combine them with buttermilk, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients, stirring until just combined.
Preheat your waffle iron according to the manufacturer's instructions.
Grease the waffle iron with a little butter or non-stick spray.
Pour enough batter into the iron to cover the surface without overflowing.
Close the lid and cook until the waffles are golden brown, about 5 minutes.
Carefully remove the waffles and keep them warm in an oven set to low heat.
Repeat with the remaining batter.
Serve immediately with your favorite toppings.