Stir the muffin mix in only until no dry streaks remain. Beating it smooth turns the casserole dry and bready instead of creamy.
Skip the sugar for a savory Southern-leaning version, or use the full 2 tablespoons for the sweeter Midwestern style.
Serve alongside roast turkey, baked ham, barbecued pork, mashed potatoes and gravy, or braised collard greens.
Add 1 cup shredded sharp cheddar and 1 seeded diced jalapeno for a Tex-Mex street corn version.
Assemble up to 24 hours ahead, refrigerate unbaked, and add 8 to 10 minutes to the bake time.
Leftovers keep 4 days refrigerated. Reheat covered at 325 F for 20 minutes, or microwave individual portions with a damp paper towel over the top.
For a crisp finish, run the baked casserole under the broiler for 90 seconds.