Bake the potatoes. Heat oven to 425F. Toss potatoes with olive oil, salt, pepper, and garlic powder. Spread on a sheet pan and roast 25 to 30 minutes, until tender and the skins look a little wrinkly and dry.
Cool slightly. Let potatoes rest 5 to 10 minutes, just until you can handle them.
Slice and scoop. Cut each potato in half. Use a small spoon to scoop out a little of the center, leaving about 1/4 inch of potato attached to the skin.
Crisp again. Place potato halves cut-side up back on the sheet pan. Bake 8 to 10 minutes until the edges are crisp.
Add toppings. Sprinkle cheese into each potato bite and top with bacon if using.
Melt and brown. Bake 5 to 7 minutes more, until cheese is melted and bubbly.
Finish. Top with a small dollop of sour cream and sprinkle with green onions. Serve immediately.