Heat oven to 375°, place 2 cups of diced butternut squash to the side. Combine the remaining squash with 3 Tbsps olive oil, 1 tsp paprika, and black pepper (to taste.) Line a baking sheet with aluminum foil, and bake squash for 30 minutes.
While the squash roasts, heat your pasta water up! In a separate large pan over medium heat, add 1 Tbsp of olive oil, the two cups of butternut squash, 1/2 tsp paprika, and black pepper (to taste.) Cook 5 minutes, stirring occasionally.
After the squash is starting to get softer, push off to the sides of the pan, creating a well. Add your pancetta and let cook in center of pan for about 5 minutes. This will help it get a little crispy!
Mix the squash and the pancetta together, raise heat slightly higher, and cook another 10 minutes, mixing frequently, and making sure everything in the pan is evenly disturbed (again to help the pancetta get a crispy outside.)
Add garlic, onion, and sage, and cook stirring frequently for another 10 - 15 minutes, until pancetta is browned and crispy, and squash is soft. Take off heat an place to the side.
To make the butternut squash puree, add about 4 - 4 1/2 cups of roasted squash to your blender or food processor, along with the reserved pasta water. You may have some roasted squash leftover for a snack!
Blend the squash and pasta water together until smooth. Add parmesan cheese and black pepper and blend into the squash puree.
Mix cooked pasta, squash puree, and squash and pancetta mixture together and serve with additional parmesan cheese.