In a large microwave safe bowl, combine sweetened condensed milk and chocolate chips. Microwave in 30 second intervals, stirring well, for about 1 minute, until smooth. Add in marshmallow and heat an additional 30-60 seconds, until smooth.
Refrigerate for 2 hours. Using a small metal scoop (about 1 tablespoon size), drop scoops of filling onto a parchment paper lined baking sheet. Freeze truffles for one hour.
Using a toothpick, dip truffle into melted chocolate, tapping the side of the bowl to remove excess. Sprinkle immediately with crushed graham crackers. Repeat. Store in airtight container in refrigerator or freezer. ENJOY.