Wash and scrub potatoes thoroughly. Pat dry and poke each potato a few times with a fork to allow steam to escape while baking.
Rub potatoes with oil and sprinkle with salt.
Place directly on the oven rack or on a baking tray and bake for 45 for 60 minutes, or until potatoes are tender when pierced with a fork. Remove potatoes from the oven and let them cool slightly.
Cut potatoes in half lengthwise. Carefully scoop out the potato flesh, leaving the shell intact. Place shells on a baking tray and set aside.
In a large mixing bowl, using a potato masher or fork, mash the potato flesh.
Mix in the sour cream, milk, butter, half the crumbled bacon, ½ cup shredded cheddar cheese, half the chopped green onions, salt, and pepper until well combined.
Spoon the potato mixture into the shells, dividing equally between the 8 potato shells. Sprinkle filled potato halves with remaining cheese and bacon.
Place potatoes in the oven and bake for 15 to 20 minutes, or until the cheese is melted and bubbly.
Remove from the oven and garnish with remaining chopped green onions. Let the potatoes cool for a few minutes before serving.
Notes
Choose baking potatoes of a similar size if possible.
Leave about ¼ to ½ inch of potato on the skin so it stays firm enough to hold the filling.
Use a freezer bag with a corner snipped off to pipe the mashed potato filling into each potato shell.
Twice baked potatoes can be assembled and refrigerated up to 2 days ahead of time. They also can be assembled and frozen for a quick side dish.