Preheat your oven to 400°F (200°C). Peel and dice the butternut squash into small cubes, toss with olive oil, salt, and pepper, and roast for about 20-25 minutes until tender.

While roasting, bring a large pot of salted water to a boil. Cook pasta according to package instructions until al dente, reserving a cup of pasta water before draining.

In a skillet, heat olive oil over medium heat. Add chopped onions and minced garlic, sautéing for about 5 minutes until translucent.

Transfer roasted squash to a blender with sautéed garlic and onions, vegetable broth, and cream, and blend until smooth.

Return the sauce to the skillet, warm through, and adjust seasonings with salt, pepper, and Parmesan cheese. Add reserved pasta water if needed to thin the sauce.

Combine drained pasta with the sauce, tossing to coat and letting it absorb flavors for about 1-2 minutes.

Serve topped with additional Parmesan cheese, fresh herbs, and nuts if desired.