Scrub the potatoes clean.
Preheat the oven to 275 degrees Fahrenheit.
Line a baking sheet with foil and place the potatoes on it.
Rub each potato with a little olive oil, salt, and pepper, coating all sides of the potatoes. Use as much or as little as you want of these seasonings to make the sweet potato just the way you like it.
Bake for about 2 ½ hours. That should give you potatoes that are caramelized on the bottom and soft on the inside.
Warm up the broiler and run your potatoes below it. Depending on your broiler, this can take anywhere from 2-10 minutes. You want the potatoes to become slightly charred on the top.
Allow the potatoes to cool slightly, on a wire rack, if possible. Crush the top of the potatoes slightly with your hand to reveal the inner flesh. Season the potatoes with some salt and top with butter if you like.