In a skillet over medium-high heat, brown the Italian sausage in olive oil until fully cooked and crumbly. Drain excess fat.
Transfer the browned sausage to a 6-quart slow cooker.
Add the cubed butternut squash, diced onion, and minced garlic to the slow cooker vessel.
Pour the chicken bone broth over the ingredients and stir in the sage, thyme, salt, and black pepper.
Secure the lid and cook on high for 4 hours or low for 7 to 8 hours until the butternut squash is tender when pierced with a fork.
To reach desired consistency, remove approximately 2 cups of the cooked squash and broth, blend in a high-speed blender until smooth, and return to the pot.
Stir in the heavy cream and serve hot, garnished with fresh parsley for brightness.