On a baking sheet, toss the diced butternut squash with 1 tablespoon of olive oil, salt, and pepper. Roast for 25-30 minutes or until tender and caramelized.
While the squash is roasting, cook the pasta according to package instructions. Drain and set aside.
In a large skillet, heat the remaining tablespoon of olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes.
Add the minced garlic and cook for an additional minute, until fragrant.
Once the butternut squash is done roasting, add it to the skillet with the onion and garlic. Pour in the vegetable broth and bring to a simmer.
Use an immersion blender to blend the mixture until smooth. If you don't have an immersion blender, transfer the mixture to a regular blender and blend until smooth, then return to the skillet.
Stir in the heavy cream and ground nutmeg, adjusting the seasoning with salt and pepper to taste.
Add the cooked pasta to the sauce, tossing to coat evenly. Cook for an additional 2-3 minutes to heat through.
Serve the pasta warm, topped with grated Parmesan cheese and chopped parsley.
Notes
You can substitute the heavy cream with a plant-based alternative for a lighter version.