These are traditional, yeasted waffles adapted from a Cooks' Illustrated article published in March, 2004. The waffles are quite rich; buttering them before eating is not compulsory and, to some, may even be superfluous.
Heat milk and butter in small saucepan over med-low heat until butter is melted, 3-5 minutes. Cool until warm to touch.
Meanwhile, whisk flour, sugar, salt, and yeast in a large bowl to combine. Gradually whisk warm milk/butter mixture into flour; continue to whisk until batter is smooth.
In small bowl, whisk eggs and vanilla until combined then add egg mixture to batter and whisk until incorporated. Scrape down sizes of bowl with rubber spatula, cover with plastic wrap and refrigerate at least 12 and up to 24 hours.
Heat waffle iron. When iron is hot, remove batter from fridge and whisk to recombine (batter will deflate). Bake waffles according to manufacturer's instructions.
Serve immediately or place waffles ona wire rack set on a baking sheet, cover with a clean kitchen towel, and place in a 200 degree oven. When final waffle is in the iron, remove the towel to crisp the waffles for a few minutes.
Note: The batter must be made 12-24 hours in advance. The author prefers texture of waffles made in classic iron, but a Belgian maker will work; though, it will make fewer waffles.