The day or night before, dissolve the yeast in 1 1/2 cups of warm water, mix with the flour and salt and let it stand overnight. (If you use quick-rise yeast, you need to let it stand for only 3 or 4 hours.)
The next morning, add the other ingredients, folding them into the raised flour-yeast mixture just until they're mixed.
Preheat the waffle iron for 3 to 5 minutes, according the manufacturer's directions, while the batter is standing.
Spray both grids of the waffle iron with oil. Pour or ladle the batter into the center of the iron, covering no more than two-thirds of the iron’s surface for the first waffle. Adjust the amount as needed for subsequent waffles.
Bake each waffle for 3 to 5 minutes, or until it can be removed easily, spraying the waffle iron grids with oil prior to each waffle.