Line 8-inch-square baking pan with foil.

Combine sugar, evaporated milk, butter and salt in medium heavy - duty saucepan. Bring to a full rolling boil over medium heat, stirring constantly. Boil, stirring constantly, for 4 to 5 minutes. Remove from heat.

Stir in marshmallows, morsels, nuts and vanilla extract. Stir vigorously for 1 minute or until marshmallows are melted. Pour into prepared baking pan: refrigerate for 2 hours or until firm. Lift from pan:remove foil. Cut into pieces.