COOK pasta as directed on package, omitting salt.
MEANWHILE, cook cream cheese, milk, Parmesan and butter in large saucepan on low heat until cream cheese is completely melted and mixture is well blended, stirring frequently. Add pumpkin and seasonings; stir. Cook 2 to 3 min. or until heated through, stirring occasionally.
DRAIN pasta; place in large bowl. Add cream cheese sauce; toss to coat.