Melt the chocolate in a microwave-safe bowl in 30-second intervals, stirring until fully melted. If too thick, stir in coconut oil until smooth.
Crush the graham crackers into small pieces using a plastic bag and rolling pin or by hand.
In a large mixing bowl, combine melted chocolate, miniature vegan marshmallows, and crushed graham crackers. Fold together until well coated.
Drop spoonfuls of the mixture onto parchment-lined baking sheets, shaping them into mounds.
Sprinkle graham cracker crumbs, sea salt, or sprinkles over the top before the clusters set completely.
Chill in the refrigerator for about 30 minutes or until firm to the touch.