Cook the bacon in a large stock pot over medium heat. Remove the bacon and save for later to crumble on top of the soup.

Add butter and onions to the bacon fat in the crock pot. Cook the onions for 20 minutes, until they turn soft and golden.

Stir in the squash, thyme, water, broth, and salt. Bring to boil. Cover and reduce to a low simmer and cook for 40 minutes.

Remove the thyme and use an immersion blender to puree the soup. Add pepper to taste and serve immediately with crumbled bacon on top.

Soup can be made up to 3 days ahead and leftovers should be refrigerated.