Yukon gold potatoes cook in the slow cooker, then get mashed with butter, sour cream and milk for a creamy side that serves 10. No boiling or draining needed.
Spray the inside of a slow cooker with cooking spray. Add the chopped potatoes and water. Cover and cook on high for 5–6 hours or low for about 8 hours, stirring every hour or so, until the potatoes are very tender and mash easily with a fork.
Without draining, mash the potatoes and remaining cooking water directly in the slow cooker using a potato masher. If using a hand mixer, mix briefly on low just until mashed.
Avoid an immersion blender or food processor, which can make the potatoes gluey.
Stir in the butter, sour cream or yogurt, milk, salt, garlic powder, onion powder and black pepper. Taste and add any additional seasonings or milk if needed to reach desired flavor and consistency.
Serve immediately or keep the potatoes in the slow-cooker on the warm setting until serving.
Notes
Make ahead: Peel and chop potatoes up to one day ahead. Refrigerate covered with cold water, then drain before adding the fresh water called for in the recipe.
Storage: Refrigerate leftovers in an airtight container for 3–4 days. Reheat on the stovetop or in the microwave with a splash of milk as needed.