Can you still use it to make cake balls? It doesn't seem like it would go "bad" - like it would hurt you - but I wouldn't want to risk trying to make a regular cake out of it b/c I think it might come out a little "deflated" or not rise as high as normal.
Has anyone attempted using year-old cake mix? I'd like to still be able to use it if I could, and cake balls seemed like a perfect idea.
The absolute worst thing is that you would waste some oil and eggs. If you really want to try it.. go ahead.
Checking the expiration date on the cake mix I have indicates that it's supposed to still be good until November of next year, so I suspect that the cake mix you have should work just fine to make a normal cake.
I've used an old cake mix before, and it was okay. It didn't quite rise as high as it should have, but the difference was less than a quarter inch.
Unless the internal packaging has been opened/ripped and air got in, I would go ahead. Like Gingoodies said, the worst thing you'll lose is a few eggs, water and oil (and heating the oven, but that's only pennies for one cake).
Before you go all out and completely decorate it, taste a bit of the levelling slice.
Expired mixes don't rise as much because the leavening agents are no longer active.
I accidentally used one for a character pan a few years ago and it came out like a thick cookie. It also had a stale taste, like pretzels out of a bag that's been left open.
I find that if you mix a fresh one with an old one, you can't tell the difference.
In the same vein, I always throw away baking soda or baking powder that has been opened for more than a year (I mark the can with the date that I open it). They just don't do their job well after that point.