Peel the potatoes. Be sure to rinse off any dirt that is left on the potatoes after peeling. Cube into 1/2-1 inch pieces. Add to the slow cooker.
Pour over water to cover the potatoes but do not fill water to the brim of the slow cooker, at least leave an inch.
Place the lid on the slow cooker on HIGH for 4 hours.
When the cooking time is up, drain the water off the potatoes. I do this with 2 potholders, using the lid to hold the potatoes in, but leaving a crack for the water to come out.
Add the stick of butter to the drained potatoes. Bury it into the potatoes while you set up a handheld mixer. Blend the butter into the potatoes on medium speed, then add the heavy cream, salt and pepper (if you are using it). Blend until smooth and fluffy. Add additional cream (or milk) if needed. (Be careful not to scratch up your slow cooker with the mixer, avoid hitting the sides or bottom with the beaters). You can use a potato masher if you do not have a hand mixer.
Taste and see if you want to season with additional salt.
Serve and enjoy!
Video
Notes
Freezing: Potatoes and cream change after being in the freezer. Potatoes get grainy and cream separates. I do not recommend freezing mashed potatoes.