1. Cook pasta in about 3 quarts boiling water until just barely tender to bite, 7 to 9 minutes. Drain.
2. Meanwhile, in a 10- to 12-inch nonstick frying pan, combine onion, garlic, and butter. Stir often over medium-high heat until onion is limp, about 5 minutes.
3. Add neufchâtel cheese and stir until melted, about 3 minutes. Stir broth and wine into pan and mix until blended. Add basil and stir until wilted, about 2 minutes.
4. Add pasta to sauce and stir until pasta is coated with sauce. If sauce gets too thick, stir in a little water to thin. Spoon onto plates. Add parmesan, salt, and pepper to taste.