Spray slow cooker with cooking spray. Dump in the frozen cubed potatoes, chicken broth, water, diced onion, salt, and pepper. Stir together.
Cover with lid and cook on LOW for 6-8 hours.
When done cooking, mix together half & half milk and flour in a small bowl. Pour into the soup and add the cubed cream cheese. Cover with lid and let cook and additional 30 minutes.
If I'm not serving the soup right away, I will add the milk/flour mix and cream cheese, then cover with the lid and set the crock pot to the warm setting for 1-2 hours. It keeps well on the warm setting if needed.
Serve with bacon pieces, shredded cheese, and green onions.