Place the butternut squash, apple, garlic, shallots, chicken broth, cayenne pepper, salt, pepper, sage, and nutmeg in the crock of your slow cooker.
Stir everything to combine.
Put the lid on the slow cooker and cook on high for 3-4 hours, or low for 6-8 hours.
Remove the lid and use an immersion blender to puree the soup until it is completely smooth.
Alternatively, you can transfer everything to a blender to puree the soup.
Stir in the cream and serve with pumpkin seeds for a garnish if desired.
