The s'more — a roasted marshmallow and a piece of chocolate sandwiched between two graham crackers — is the definitive American campfire food, the dessert that every American child makes and that every American adult remembers. The first printed recipe appeared in the 1927 Girl Scout handbook as "Some Mores." The technique is entirely about the marshmallow: the roasting over open flame, the patience required to achieve a golden-brown exterior without catching fire, the moment when the hot marshmallow meets the cold chocolate and begins to melt it.
A large marshmallow skewered on a stick (or a long fork), held 10-15cm above the glowing embers (not the flame — the embers provide even radiant heat; flame chars the exterior instantly). Rotated slowly until the exterior is uniformly golden-brown and slightly puffed. The hot marshmallow is pressed between two graham cracker squares with a piece of chocolate (Hershey's is traditional) sandwiched against it. The marshmallow's heat begins to melt the chocolate. The assembly is compressed gently and eaten immediately — the exterior is slightly crispy, the interior is molten, the chocolate is half-melted, and the graham cracker crumbles provide the structural crunch.
1) Embers, not flame — patience produces a golden, evenly roasted marshmallow. Flame produces a charred exterior and cold interior (which some people prefer — the debate is as personal as the fudgy/cakey brownie debate). 2) Rotate constantly — even browning requires attention. 3) The chocolate should be at room temperature or slightly warm — cold chocolate resists the marshmallow's heat and doesn't melt properly.
The gourmet s'more movement: artisan marshmallows, single-origin chocolate, cinnamon or chocolate graham crackers. The upgrade is real and the product is better. But the Hershey's-Jet-Puffed-Honey Maid original carries the cultural weight and the nostalgia.
James Beard — American Cookery; Girl Scout Handbook