Preheat oven to 400°F (200°C). Rub the potatoes with olive oil and pierce a few times with a fork. Place directly on the oven rack and bake for 60 minutes, or until tender.
Remove potatoes from the oven and let cool for 10-15 minutes until safe to handle. Cut each potato in half lengthwise.
Carefully scoop out the inside flesh of the potatoes into a large bowl, leaving about a 0.25-inch thick shell. Place the empty potato shells on a baking sheet.
Mash the potato flesh with the softened butter, sour cream, milk, salt, and pepper until smooth and creamy.
Fold in 1 cup of the cheddar cheese, half of the crumbled bacon, and half of the green onions.
Spoon the mashed potato mixture evenly back into the potato shells. Top with the remaining 0.5 cup of cheddar cheese and remaining bacon.
Bake for an additional 15-20 minutes until the cheese is melted and bubbly. Garnish with the remaining green onions before serving.
Notes
For a crispier skin, rub the outside of the potato shells with a little more olive oil before the second bake.