Creating Butternut Squash Ravioli Sauce is simple when following these easy steps:

1. Begin by peeling and dicing the butternut squash into small cubes.
2. In a large pot, heat the olive oil over medium heat.
3. Add the chopped onion and sauté until translucent, about 5 minutes.
4. Stir in the minced garlic and continue to sauté for another minute until fragrant.
5. Add the diced butternut squash to the pot and stir well.
6. Pour in the vegetable broth, then cover and simmer for about 15 minutes or until the squash is tender.
7. Once the squash is cooked, use an immersion blender to puree the mixture until smooth. (Alternatively, transfer to a blender in batches.)
8. Return the smooth puree to the pot and stir in the heavy cream.
9. Sprinkle in the ground nutmeg and thyme, seasoning with salt and pepper to taste.
10. Simmer for an additional 5 minutes to heat through and meld the flavors.
11. Drizzle the sauce over cooked ravioli, tossing to coat evenly.
12. Serve immediately, garnishing with grated Parmesan cheese and basil if desired.

These clear steps will guide you in creating this incredible sauce effortlessly.