Preheat oven to 400 F. Option to line a baking sheet with foil for easy clean up.
Place butternut squash and onions on prepared baking sheet. Drizzle with oil, and sprinkle with 1 teaspoon salt and 1/2 teaspoon pepper, then toss to combine. Spread veggies in a single layer on the baking sheet, then drape bacon over the top. Bake in preheated oven until the veggies are soft and the bacon is fully cooked, 30-35 minutes.
Place bacon aside on a plate, and transfer veggies to a food processor. Add ricotta, and process until smooth. Taste and adjust the salt and pepper to. your liking.
Once the bacon has cooled complete, chop into small pieces.
Meanwhile cook the pasta according to package instructions, or follow my instructions for prepping veggie noodles (below). If using traditional pasta, reserve 1 cup of cooking liquid. For veggie noodles, grab 1/2 cup of vegetable broth.
To the drained pasta pot, melt the butter. Just before it starts to bubble, add the garlic and sage. Stir constantly until the garlic is fragrant, about 2 minutes. Add the pureed butternut squash, 1/2 cup of reserved pasta water or veggie broth, shredded mozzarella, 1 teaspoon of salt, and 1/2 teaspoon of pepper. Stir to combine.
Stir in the pasta, and add more pasta water/veggie broth if needed to coat the noodles. Taste and adjust to your liking, I always add an additional teaspoon of salt here.
Top pasta with chopped bacon and more sage if desired. Enjoy!