KrusteazHoney Cornbread and Muffin Mix, 15 Ounce (Pack of 12)

Q: Can it be used past the expiration date?

Yes. It's not really an expiration date. It's a best by date. A few months over usually won't matter at all, especially if you are low humidity. Over six months it won't taste as good and you might need to add extra baking powder to get it to rise. It won't make you sick, but also won't be as nutritious or tasty. The fats will eventually go rancid and it will smell off. It's a waste of you other ingredients to use it then because it won't taste good. It depends on how and where it was stored how long it will last, humidity and temperature being factors. If you open it and it smells off, don't bother cooking it. I wouldn't use it much over a year past the best by date.

Q: Can it be used in a bread machine?

Depends on the bread machine. My Zojirushi had a cake menu that makes cornbread. It doesn't go through the rising and beating down and whatever other steps are required to make yeast bread. So I'd say yes it can be made in (my) bread machine. I plan to try it in a rice cooker, too. Lot of people are baking just this type of bread in them now. My Zoji rice cooker also has a cake setting. Love gadgets.

Q: Can you bake two boxes in a 9 1/2 x 13 pan or is it best to stick to two separate 8 x 8 pans?

I would try it, if once your 9 1/2 x 13 is filled enough for it to rise an inch or so, you should be safe, test to see if it is done after recommended time, you may need a few more minutes. Good luck, why mess up two pans when one should do.