Cook pasta according to package directions for al dente. Meanwhile, in a large skillet, cook onion in oil over medium heat until softened, 4-5 minutes. Add garlic, cook 1 minute longer. Stir in chicken and mushrooms. Cook, stirring frequently, until chicken is no longer pink, 5-7 minutes. With a slotted spoon, remove mixture; set aside. , To the same skillet, add wine and broth; bring mixture to a simmer. Cook until liquid is reduced by half, 15-20 minutes. Reduce heat to low; add cream cheese and butter, whisking until melted. Whisk in cream, salt and pepper. Add chicken mixture to pan; heat through on low. Toss with pasta and 1/4 cup Parmesan cheese. Top with remaining 1/4 cup Parmesan cheese and, if desired, parsley.