Cook pasta as directed on package; drain.
Meanwhile, melt butter in large saucepan on medium heat. Add cream cheese and milk; stir 2 min. or until cream cheese is completely melted and sauce is well blended, stirring constantly with whisk. Stir in 2 Tbsp. Parmesan.
Add pasta to sauce with zest; stir until evenly coated. Top with pepper and remaining Parmesan.
