Place your graham crackers in a food processor with the melted coconut oil and pulse until the crackers resemble fine crumbs.
Spoon the crushed graham crackers into the tart pans and press down tightly all along the bottom and up the sides.
Melt the dark chocolate with the coconut cream over medium heat until the chocolate is melted.
Spoon about 2 Tbsp of the fudge into the mini graham cracker pie crusts
Sprinkle the mini marshmallows on top of the chocolate layer. Bake the tarts in the oven, while on top of the cookie sheet, until the marshmallows are golden brown and puffy.