Put the milk, butter, and sugar in a saucepan over medium high heat. Put a candy thermometer on the side and stir frequenyly until the mixture reaches 234 degrees.
Remove from heat and stir in the chocolate chips and marshmallow cream.
Once everything is combined gently fold in 2/3 of the graham cracker pieces and marshmallows.
Pour into the prepared pan and sprinkle with remaining graham cracker pieces and marshmallows. Press into the fudge.
Allow to cool for 4 hours or place int he refrigerator.
When ready to eat use the foil to remove from the pan.