Peel, quarter, and boil potatoes for 15-20 minutes or until soft. Drain potatoes and and beat with a mixer until smooth. Add milk, cream cheese, sour cream, parsley, garlic salt, and nutmeg. Beat at a medium-high speed until nice and creamy. Add salt to taste keeping in mind that the cheese and bacon will add a little salt later.
Spoon into a baking dish that has been sprayed with cooking spray. Top with cheddar cheese and bacon. Cover and bake for 30 minutes. Uncover and bake for an additional 10 minutes or until cheese melts.