Add a small puddle of chocolate syrup to a plate. Dip the rim of the glass in the chocolate syrup and then into the crushed graham crackers
Add the coffee, marshmallow fluff, milk, chocolate syrup, and whiskey to a blender. Blend until it's smooth and combined.
Fill a cocktail shaker up with ice. Add the blended drink into it and shake for 15 seconds, until completely chilled.
Add a dollop of marshmallow fluff, a drizzle of chocolate syrup, and a layer of crushed graham crackers to your cocktail glass. Fill the rest up with ice.
Pour the drink into the glass.