Wellesley College Fudge

This is the fudge recipe that's from Wellesley College.

Ingredients:

2 cups granulated sugar

1 cup heavy cream

2 oz. unsweetened chocolate, chopped

1 tablespoon butter

1/2 lb marshmallows 

Combine sugar and cream and cook over moderate heat. When this becomes very hot, add the chocolate. Stir constantly. Cook until mixture reaches soft-ball stage (238 degrees). Remove from heat and add butter and marshmallows. Mix until fudge starts to thicken. Transfer to a buttered tin. Cut into squares before fudge hardens completely.