Preheat your oven to 350 degrees.
Line a 9 inch square dish with parchment paper so that the parchment comes up the sides about 1 inch higher than the rim of your baking dish.
Crush your Graham crackers in a bag, blender, or food processor until fine.
Mix the graham cracker crumbs with melted butter then press into the bottom of the parchment lined pan.
Place in the oven for 12-14 minutes.
Remove and allow the crust to cool for about 10 minutes.
Sprinkle the marshmallows on top of the crust.
In a medium sized sauce pot on medium to medium low pour in the chocolate chips, sweetened condensed milk, salt and vanilla extract.
Stir continuously to prevent burning the chocolate until completely melted.
Pour the melted mixture over the marshmallows and gram cracker crust and spread it out.
Place the fudge into a refrigerator until cooled and solid about 30 minutes.
Cut into 1-2" squares.