There is a sign for s'more (or smore) but as of 2020 almost no one knows it.
Most will tell you to "spell" it. Some will tell you to describe it.
However for your eating pleasure here is the sign:
[Graphic goes here.]
You hold your hands slightly overlapping bent-(compressed)-"C" hands (as if holding a s'more).
Then you squish it down (a little bit) twice (as if pressing the chocolate and marshmallow inside the graham crackers.
Notes:
Reference: Metsch, Noemi (April 24, 2018) Comment under thread: "What's your sign for s'mores?" Facebook: Retrieved from https://www.facebook.com/groups/ASLTHAT/permalink/2157715447793284/?comment_id=2158420111056151
Notes: