Whisk all of the ingredients together in a large bowl, forming a relatively thin batter rather than a dough. (The batter will bubble and rise, so don’t use a bowl that’s too small.) Cover with plastic wrap and leave at room temperature overnight.

Heat a griddle (or large frying pan) on medium heat with 6 muffin rings arranged on the griddle. Spray or brush the insides of the rings with oil, and let them heat with the griddle.

When the griddle is hot, ladle or pour the batter into the rings, filling them to about ¼ inch below the top of the rings. Cover the griddle—a sheet pan turned upside down on top of the rings is perfect—and reduce the heat to medium low. Cook until the top of the batter is set and has started to pull away from the sides of the rings, about 8 minutes.

Use a small spatula to flip the muffins (and rings) over, cover the pan again, and cook for another 5 minutes. You should now be able to slip the muffins out of the rings. If some need encouragement, slide a thin knife around the insides of the rings, then remove the rings.

Continue cooking the muffins until they are cooked through and the top and bottom are lightly browned—a skewer or small knife inserted into a muffin should come out clean and if you lift a muffin, it should feel light for its size. It’s actually okay if the muffins are still a little bit moist inside because they’re not really done until they’re toasted. But you don’t want them to be wet or soggy.

(Editor Note: When properly cooked in the middle, the muffins should be about 200°F on an instant-read thermometer. If you don't think they are cooked through, preheat your oven to 350°F, and bake them for 5 to 10 minutes, or until they're cooked through.)

Let the muffins cool completely on a rack.