In a big mixing bowl, combine flour, sugar, salt and instant yeast. Make sure you use a pretty big bowl; the dough will expand a bit. Whisk in the melted butter and warm water. Mix until the dough comes together (it's ok if it’s a bit lumpy). Cover the top with plastic wrap and let the dough sit at room temperature for at least one hour. If making the waffles later, you can refrigerate it overnight after letting it rest—just make sure you bring the dough back to room temperature before using. 

Preheat a thick waffle maker to medium heat.

To make the waffles, remove the plastic wrap from the batter bowl. The batter should be bubbly and mildly fragrant from the yeast. Add the eggs and milk to the batter, and whisk.

Brush the waffle maker with a little melted butter or spray with some nonstick cooking spray. Pour an even layer of batter into the waffle maker and cook for 6-8 minutes or until crispy and brown.

Serve immediately or place the waffles on a cooling rack set over a sheet tray and keep warm in a 200°F degree oven.