Grease the waffle iron (if required), before preheating.
In a large mixing bowl, beat together the eggs, then add the buttermilk, butter and vanilla and mix well.
In a separate bowl, combine the dry ingredients and then sift these into the egg mixture. Stir till fully incorporated. (If the mixture seems a bit dry, add a bit of milk.)
Spoon the batter into the waffle iron and cook according to manufacturer's instructions, till crisp and golden. Serve warm.
Notes
Always start with a preheated waffle iron.
I used a 7-inch regular waffle iron to make 6 waffles. However, if your waffle iron makes extra thick waffles, this recipe will make 4.