Preheat the oven to 375º.

Place the potatoes on a parchment-lined sheet tray, prick with a fork in a few places, and roast until they are knife tender, 45 minutes to 1 hour. Allow the potatoes to cool a bit.

While the potatoes are cooking, prepare the bacon. Lay the slices of bacon on a parchment-lined sheet tray, and bake until golden brown. Allow to cool. Once cool, crumble or cut the bacon into small pieces. Set aside.

Peel the skin off of 1 potato, and place it in a medium-size bowl.

Cut the remaining 2 potatoes in half lengthwise. Using a spoon, scoop out the inside of the potato halves leaving an 1/8-inch-thick wall inside the skins. Place the 4 halves in a baking dish, season with salt and pepper to taste and set aside.

Using a potato masher, mash the potatoes with the butter, sour cream, milk or buttermilk. Add a touch more milk if desired. Stir in the crispy bacon, scallions and most of the cheese. Season with salt and pepper to taste.

Using a spoon, refill the shells with the potato mixture, mounding it slightly, and top with a sprinkling of the remaining cheese.

Bake until golden brown on top and hot all the way through, 25 to 30 minutes.