S'mores are a type of snack food that is known to be popular in certain regions of Earth, though the first s'more wasn't created on The Land until LY 590. (The name is a contraction of "some more," as in "I want s'more," because they are considered too good to eat just one.) S'mores consist of three ingredients: graham crackers, chocolate bars, and pâté de guimauve (or guimauve, for short).
Graham crackers were first made on the Land in LY 565. The man who created them was a spirit-talker named Lester, who learned the Terran name for the crackers from one of his spirit friends, and chose to give them the same name on the Land. The version of the cracker that Lester invented was closer to a modified version that had appeared later on Earth than it was to the original Terran graham crackers, which were of a healthier nature. Like the original, Lester's crackers were made from unbleached wheat flour combined with wheat bran and germ. But unlike the original, they are sweetened with honey and cinnamon. Five years after inventing the cracker, Lester and his wife had a son, whom they named after the cracker.
Pâté de guimauve is a confection which had been made on the Land for a few centuries, by the time graham crackers were introduced. It is made from sap derived from the roots of guimauve plants, mixed with water, sugar, and corn syrup. When making s'mores, cubes of guimauve are roasted over a fire, thus caramelizing them. They and the chocolate bars are then sandwiched between two graham crackers.
It was in 590 that Graham (Lester's son), an adventurer, first decided to put these ingredients together, while camping in the woods somewhere outside his home village of Plist. While not technically a spirit-talker himself, he had occasionally spoken with his father's spirit friends, including the one who'd informed Lester of the name "graham cracker." That spirit had at some point mentioned s'mores to Lester, but he'd never bothered trying to make them. It wasn't until 590 that the same spirit mentioned s'mores again, to Graham, shortly before the camping trip in question, and Graham decided to bring the ingredients with him to try. (He could have tried making s'mores at home, but the spirit had told him it was traditional on Earth to make them while camping out.)
When Graham returned from his trip and told his friends and family about s'mores, which he deemed "about the best thing ever," he embellished the story by saying he'd met a dragon who had used its fire to roast the guimauve cubes for him, though since at the time most non-Sorreters were unaware of the existence of dragons on the Land (that wouldn't be revealed to the general public for another five years), no one believed him. Since then there has been speculation that he may have been telling the truth, but it is now impossible to know for sure. But what is known is that ever since Graham first introduced them to the Land, they have been a popular treat among campers and travelers everywhere.