if you to cheat - Trader Joe's cowboy bark is pretty much that recipe. You could buy a few bags, surround with some other candy and there you go !
I've never heard of this! Looks like I need to get that and the cowgirl bark (for DH) before our upcoming trip.
It also sounds like it fits the OP's need for being easy to carry on public transportation, doesn't require use of the oven or stove (or, even, the kitchen!), can sit out all day, is grazing-friendly, isn't the same as what others are already bringing and would fit in with the other food being brought.