1Combine sugar, butter and milk in heavy saucepan, bring to full rolling boil over medium heat ~ stir constantly for 5 minutes over medium heat~ stir constantly to prevent scorching. Remove from heat stir in butterscotch chips until melted. Add marshmallow, nuts, and vanilla.
Beat until well blended.
Pour into greased 13 x 9 inch pan.
Cool at room temperature ~ Cut into squares.
Makes appoximately 3lbs.