Run it under your faucet or filtered water tap. Wrap in foil, then into a low oven. You could then uncover and butter the top for a quick broil/toasting.

Should work.

I do this when I pull breads out of the freezer.

Clever!

You can also use it for crumbs. If it's the sugary kind, it can make a nice streusel. If it's not sweetened, you can use it like cornmeal as a thickener, like in chili, coating, etc.

Years ago I had a stack of good locally made corn tortillas in a cooler on a road trip. (they were on top with fridge ingredients. Not down at the bottom with melted water gunk). A bag of ice on top at some point soaked them. At our destination, I stacked a few, rubbed with a bit of oil and cut in half, re-peat until I had chips. Single layer I toasted them. The extra moisture gave them some puffing and a bit flaky. The rest I froze in 6 each packets for taco nights....put in oven wrapped in foil straight from the freezer when needed.

So now, when I want to make my own chips from corn tortillas, I wet them first.

Split it and toast it....

I would use it to make cornbread stuffing - it's not just for Thanksgiving and Christmas - I make it all year. However, if it is sweet cornbread, it will make sweet stuffing, which I do not like. I never put sugar in cornbread.

I'm going to try the wet and bake method! If it doesn't work I'll make Lars' stuffing! Thanks for the ideas y'all!

Second vote for cornbread dressing.

If not sweet, you could make croutons and use in salads, or even a panzanella salad, which sounds yummy to me.

Lots of ideas here, including cornbread pudding and fruit crisp:

https://food52.com/blog/11687-beyond-stuffing-other-uses-for-stale-cornbread

I've made croutons from stale cornbread - good on top of chili!

seagrass

If it is sweet, it does not have many uses. But, if it is not sweet, it can be used to make a dressing, as suggested. I, personally, have many uses for leftover cornbread, but they are mostly catering to a very personal taste so I will not offer them as suggestions. I have a personal relationship with good cornbread made with good cornmeal and baked with a crusty bottom in a hot iron skillet. As a matter of fact, it is the only time when having a "crusty bottom" is a good thing.

I almost always keep left over cornbread on hand. It keeps for a good long while. You can split it open and heat it in an ungreased hot skillet and it will be as good as ever. Or, heat it in a skillet that has been graced with some butter. For a real true devotee of cornbread like myself, that is all it needs.

Being that beans and cornbread is a staple in my kitchen, the cornbread often gets heated up and enjoyed with some good beans. Or, it can be enjoyed with a bowl of soup or stew.

Just leaving cornbread out unprotected overnight should not harm cornbread.

Lke Lars, I never use sugar in my cornbread, ever!!!!

I have seen some of these cornbread mixes that create a light piece of cornbread that has a lot of air in it. That would not keep well. There is no substance to preserve. It is like some baguette loafs that are so contrived as to be light as air because they are air, and we know what happens to those when you leave them out. After a couple of days, you could almost hammer nails with it! A good cornbread recipe should give you cornbread that has moisture and substance.

Cornbread cannot be run under water. It is not like a hard baguette. Cornbread is not the same nature as a loaf of yeast bread with all the gluten structure.There is no gluten structure in cornbread like that. Water would cause it to just crumble and wash away or just get soggy.