In a large pot, sauté garlic and onion in olive oil until onions are translucent (about 5 minutes).
Add butternut squash, broth, and cream. Bring to a boil. Lower heat, cover, and allow to simmer for 15-20 minutes until squash is soft.
Pour contents of pot into blender. Add walnuts and salt. Blend until pureed.
Pour into bowls. Fill a plastic bag with sour cream, carefully cut the corner off, and pipe three circles in each soup bowl. Use a wooden skewer (or knife) to pull and drag out from the center to create the spider web from the sour cream. Top with a walnut half. Enjoy!