Cover with a clean towel or plastic wrap and let sit overnight at room temperature, 10 to 12 hours. It doesn’t have to be exact. The mixture will rise to more than double and probably fall.
Re-flour the cutter between each cut. Place each cut muffin onto the cornmeal, placing them 2 inches apart or more, as they will expand.
Let rise for 1 - 1 1/2 hours, or until almost doubled and puffy.