Preheat oven to 350°F. Spray a casserole dish with nonstick cooking spray.
If desired, peel potaotes. Dice potatoes into small bite sized squares. Place in a large microwave-safe bowl with about 1-inch of water. Cover with plastic wrap and cook on high power in microwave for about 6 minutes, or until potatoes are just starting to get fork tender. (They shouldn’t fall off the fork; they need to be a bit underdone since they’ll finish cooking in the oven.)
(If desired, you can boil the potatoes on the stove instead of using the microwave.)
Meanwhile, mix together the cream cheese, soup, spices, sour cream, and milk. Stir in the green onions and 2 cups of the shredded cheese.
When potatoes are finished par-cooking, drain them well then stir them into the soup mixture. Spread in prepared pan. Cover with foil
Bake for 30 minutes. Remove the foil and add the remaining cheese. Cook until the potatoes are cooked through and cheese is melted and bubbling around the edges, about 20-25 minutes more.
Serve hot. Store leftovers in refrigerator.