Bring a pot of salted water to a boil; prepare the pasta according to package instructions, cooked to al dente.
Place the bacon in a pan over medium heat. Cook for 4-5 minutes or until crisp.
Remove the bacon from the pan and reserve for later use. Drain most of the fat from the pan, leaving about 2 teaspoons left in the pan.
Add the onion to the pan. Cook for 3-4 minutes or until softened. Add the garlic and cook for 30 seconds.
Add the butternut squash puree and heavy cream to the pan. Season the sauce with salt and pepper to taste.
Cook for 3-4 minutes, stirring occasionally, until sauce is heated through and is starting to thicken. Stir in the parmesan cheese and cook for 1 more minute.
Drain the pasta, reserving 1/4 cup of the cooking liquid, and return it to its cooking pot.
Place the pot over medium heat and add the butternut squash sauce. Toss to combine.
If you prefer a thinner sauce, add the cooking liquid, one tablespoon at a time, until desired consistency is reached.
Sprinkle the reserved bacon over the pasta, along with the parsley, then serve.