Line a 9"x13" with foil or parchment paper and spray with non stick cooking spray. Set aside.
Bring sugar, butter and evaporated milk to a rolling boil over medium heat in a double boiler. Boil for approximately 5 minutes (stirring constantly) until the mixture has a temp of 234 F on a candy thermometer.
Then remove the mixture from heat and stir in chocolate chips and marshmallow creme. Stir until well combined and completely melted.
Next add in the vanilla extract and mix well. If you are using nuts, add them at this time too.
Pour the mixture into your prepared pan and let cool completely.
Lift the foil or parchment paper out of pan and cut into small squares.