Graham Cracker Exchange
Graham crackers really aren't crackers; they're cookies, and while the classic treat is made with them, other cookies (biscuits work, too!) could easily take their place.
Substituting biscuits (you decide if they should be chocolate-dipped or not), Biscoff cookies or shortbread cookies (original, tea-spiked or flavored with almond, lemon or lavender) for graham crackers won't profoundly change the flavor profile of the s'mores, but it will upgrade the sandwich cookie from lunchbox to ladies who lunch.
For something with a little more kick, add a little warm spice flavor by using gingersnaps instead of graham crackers, or try peanut butter cookies (salted or unsalted) to satisfy any chocolate-peanut butter craving.