Active time: 50 minutes Total time: 50 minutes, plus rising overnight
To make waffles: In a small bowl, stir together yeast and water and let stand until foamy, about 10 minutes. In a large bowl, whisk together eggs and milk. In a medium bowl, sift together cornmeal, flour, salt, and sugar. Add yeast mixture to eggs and milk. Whisk in dry ingredients, then butter. Cover bowl and refrigerate overnight.
Stir baking soda into waffle batter. Preheat waffle iron and brush lightly with vegetable oil. Cook waffles until golden and cooked through, about 3 minutes. Keep finished waffles warm in an oven in one layer to stay crisp.
To make syrup: Combine all syrup ingredients in a medium saucepan. Bring to a boil and reduce until liquid coats the back of a spoon, 10 to 15 minutes. (If not using right away, refrigerate syrup in an airtight container for up to 1 month.)
To serve, spoon warm syrup over waffles and eat immediately.