Something from the past
Reminds me of fruit leather.
Also on Instructable: "Portable/Pocket Soup"
"Louis and Clark reportedly took over 100 lbs of the stuff on their expedition across America. It was reported to have saved them from starvation on multiple occasions. It was also reportedly carried on Captain Cook‘s trip to Australia because it was antiscorbutic (preventing scurvy). Virginia planter William Byrd II said it was “a wholesome kind of Food, of very small Weight and very great Nourishment, that will secure them from Starving, in case they should be so unlucky as to meet with no Game.” One particularly awesome thing about this is that it lasts SOOOO long, it will probably outlast you.
"A cake of portable soup, thought to have originally come from Captain Cook’s supplies, survives in Britain’s National Maritime Museum in Greenwich—a flat rectangular cake stamped with a broad arrow [THE IMAGE IN THIS SECTION], looking much like a “slab of glue.” It was tested in the 1930s by food scientist Sir Jack Drummond, who pronounced it “changed very little.”"