Line a 9-inch square baking dish with parchment paper or aluminum foil. Make sure to leave an overhang so that you can easily remove the fudge from the pan.
In a saucepan, bring sugar, butter and evaporated milk to full boil, stirring constantly.
3 cups granulated sugar, ¾ cup butter, ⅔ cup evaporated milk
Cook for 1 minute, stirring constantly.
Remove from heat.
Stir in chocolates and marshmallow crème until melted and well-combined.