Cook pasta as directed on the package, then set aside.
Meanwhile, slice the mushrooms.
In a large skillet, heat butter and olive oil over medium heat. Once hot, toss in the mushrooms and sauté for 5-10 minutes, or until they begin to soften.
Mince garlic and add to mushrooms, along with 1/3 of the broth. Stir to combine; cook 1 minute more.
Add milk and salt; stir to combine. Add the cooked pasta and the remaining broth.
Stir in Parmesan, spinach, and cream cheese; cook another 2-3 minutes or until heated through and the cheese is melted.
Serve immediately with grapes on the side.