Butter inside of crock with butter and leave remaining butter on the bottom of the dish. Add potatoes and cover. Cook on high 3 hours or 5-6 hours on low.
Remove cover, once potatoes are fork tender (meaning they break apart when you put a fork into a potato), add milk and cream. Mash with potato masher until desired consistency is reached. Add remaining ingredients and stir to combine.
Serve and enjoy!
