Cook spaghetti according to package directions; drain.
Meanwhile, in large skillet, cook bacon over medium heat for 6 to 8 minutes or until crispy; transfer to paper towel. Wipe pan clean with paper towel, discarding fat.
Add cream and butter to pan; bring to boil. Boil for 2 minutes; add pasta, cheese, spinach and bacon. Toss for 2 minutes or until well coated and spinach is wilted. Season with salt and pepper to taste. Serve with additional Parmesan cheese.
Substitute pancetta or prosciutto for bacon if desired.