Toss the cubed butternut squash in 1 tablespoon of olive oil, salt, and pepper and spread them on a baking sheet. Roast in the oven for about 25-30 minutes or until tender and slightly caramelized.
While the squash is roasting, in a large skillet over medium heat, add the remaining tablespoon of olive oil. Sauté the chopped onion until translucent, about 5 minutes.
Add the minced garlic to the skillet, cooking for another minute until fragrant.
Once the butternut squash is out of the oven, add it to the skillet with sautéed onion and garlic. Sprinkle in the nutmeg and cinnamon, stirring to combine.
Pour in the vegetable broth and bring the mixture to a simmer. Cook for another 5 minutes, allowing the flavors to meld.
Using an immersion blender (or transferring to a regular blender), puree the sauce until smooth. If it's too thick, add a little more broth to reach your desired consistency.
Return the sauce to the skillet and stir in the heavy cream. Allow it to warm through. If you're using Parmesan cheese, melt it in at this point for added creaminess.
Combine the cooked pasta with the sauce, tossing gently to coat.
Serve hot, garnished with fresh sage leaves and additional cheese if desired.
Notes
For a dairy-free option, use coconut cream instead of heavy cream.
Keyword butternut squash, creamy sauce, pasta sauce