Put in large bowl then set aside: chocolate chips, butter, vanilla and marshmallow cream.
In 2 quart pan put in sugar and canned milk. Stir until sugar is dissolved then stirring constantly, bring to a rolling boil and cook for about 10 minutes or to softball stage. Pour hot mixture over the mixture in bowl, stir and beat until smooth then stir in chopped walnuts.
Pour fudge into a buttered pan (9x13 or a cookie pan for not so thick pieces). Refrigerate until solid.