As per usual, the scientifically precise, tried-and-true guidance of Cook's did not let me down. I borrowed the Smith popover pan, mixed up some batter, let it sit for about 15 minutes instead of (at least) 60, and they turned out just about perfect. Just as the recipe promised.
Let me know if you try these! They're amazingly good and are fun to fill with great things like butter and jam. We kept our leftovers in a bag in the fridge and reheated them in the microwave, which worked surprisingly well.