Knowing when and if the muffins are completely cooked can be tricky, so I have the oven preheated to 350 degrees with a sheet pan set on the center rack. I almost always find that while the muffins are browned enough on the outside, they are still a little underdone on the inside, mostly because I make huge muffins. So after they have browned on the griddle, I transfer them to the oven, cover them with foil, and allow them to bake for 15 -20 minutes.