Grease a 9×13-inch baking dish.

In a mixing bowl, combine the chocolate chips, melted butter, and marshmallow cream. Set aside.

In a heavy-bottom saucepan, heat the sugar and evaporated milk over medium heat until it reaches a rolling boil, stirring continuously.

Boil for 7 minutes while stirring to prevent burning.

Pour the hot mixture over the chocolate mixture and stir until smooth.

Mix in the vanilla and optional nuts.

Pour the mixture into the prepared pan and refrigerate until set, preferably overnight.