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 48 pieces.