MIX cream cheese spread and milk until blended.
HEAT oil in large skillet on medium heat. Add onions and garlic; cook and stir 5 min. or until onions are crisp-tender. Stir in broth and spaghetti sauce. Bring to boil.
ADD pasta; stir. Cover; cook on medium heat 5 min., stirring occasionally. Add cream cheese mixture; cook and stir 3 to 5 min. or until heated through. Cover; cook 5 min. or until pasta is tender, stirring occasionally.
STIR in spinach; cook, covered, 1 min. or just until wilted. Top with Parmesan.