Spray a crock pot with non-stick cooking spray. Mix all of the ingredients together in the crockpot, (except for the parmesan cheese and optional topping). Cover and cook on High heat setting for 4-6 hours, or on the Low heat setting 8 to 10 hours.
After cooking, ladle 1/4-1/2 of the soup (more or less according to how creamy you want it), into a blender and blend until smooth. Add pureed soup back to the crockpot with the rest of the soup, and stir in parmesan cheese. Serve with bacon if desired! Enjoy!