Peel the potatoes and cut into 1-inch chunks.
In the bottom of a 4-quart slow cooker, add the potatoes, broth, garlic powder, and onion powder.
Cover and cook on high for 3-4 hours or low for 6-7 hours or until fork tender. Each hour or so, very quickly stir the potatoes.
Once tender, use a hand masher or hand mixer to mash the potatoes until smooth.
Stir in the butter, sour cream, parsley, and cream cheese if using. Season with salt & pepper to taste. Add warmed milk or cream to reach the desired consistency if needed.
Serve or keep on warm until serving.
