Line slow cooker with foil, leaving some to overhang on the sides.
Spray with non-stick cooking spray.
Place potatoes in the slow cooker.
Add ranch seasoning, salt, pepper and bacon; stir to combine.
Top with 1/4 cup of shredded cheese.
Fold foil over top of the potatoes and place lid on slow cooker.
Cook on low for 7-8 hours or high for 4 hours.
When finished cooking, top with remaining cheese and green onions; replace cover and cook for 10-20 minutes more.