Preheat oven to 400°F (200°C). Scrub potatoes clean and dry thoroughly.
Pierce potatoes with a fork a few times; rub skins with olive oil and sprinkle with salt.
Place potatoes on a baking sheet and bake 45–55 minutes until fork-tender.
Let potatoes cool slightly until safe to handle, about 10 minutes.
Slice each potato in half lengthwise; scoop out the flesh leaving about 1/4 inch of potato attached to the skin.
Brush the insides and outsides of the shells with a bit more oil; season lightly with salt and pepper.
Return shells to the oven, skin-side down, and bake 8–10 minutes until edges begin to crisp.
Meanwhile, mash the reserved potato flesh with cream cheese, 1/2 cup shredded cheddar, sour cream, salt, and pepper until smooth.
Spoon the potato-cheese mixture into each crisp shell; top with remaining cheddar.
Return to oven 6–8 minutes until cheese melts and begins to bubble; sprinkle with crumbled bacon and scallions before serving.