Grease a 9x13 inch pan with butter or line with parchment paper. Set aside.

Break up milk chocolate bars and place in a bowl with semi sweet chocolate chips, marshmallow creme, and vanilla.

In a medium size pot, combine sugar, evaporated milk, and butter. Bring to a boil over medium-high heat. Once it starts boiling, set the timer for 5 minutes and let boil while gently stirring.

Pour the cooked sugar over into the bowl of chocolate. Stir and beat together to cool. Mix until smooth. Stir in walnuts if desired. Pour into prepared pan and smooth over.

Let fudge cool completely to set up. You can place in the fridge to speed up the process. Then cut into squares and store wrapped in plastic wrap or in an air tight container in the fridge.