Preheat your oven to 400°F (200°C).
Scrub the potatoes clean and poke them with a fork a few times. Bake them in the oven for about 1 hour, or until tender.
Once the potatoes are cool enough to handle, cut them in half lengthwise and scoop out the flesh into a mixing bowl, leaving a thin layer of potato in the skins.
In the mixing bowl, add sour cream, milk, butter, salt, pepper, and half of the shredded cheese. Mix until well combined and creamy.
Spoon the mixture back into the potato skins. Top with the remaining cheese and crumbled bacon.
Place the stuffed potatoes on a baking sheet and bake for another 15-20 minutes, or until the cheese is melted and bubbly.
Garnish with chopped green onions before serving.