Preheat your oven to 400°F (200°C).
Scrub the potatoes clean and pierce them a few times with a fork. Place them on a baking sheet and bake for about 1 hour, or until tender.
Remove the potatoes from the oven and let them cool slightly. Cut each potato in half lengthwise and scoop out the flesh, leaving a small border of potato intact.
In a mixing bowl, combine the potato flesh, sour cream, milk, butter, salt, pepper, and half of the shredded cheddar cheese. Mix until well combined and creamy.
Spoon the mixture back into the potato skins. Top with the remaining cheddar cheese and crumbled bacon.
Return the potatoes to the oven and bake for an additional 15 minutes, or until the cheese is melted and bubbly.
Garnish with chopped green onions before serving.