01 - Heat the oven to 400°F.
02 - Scrub potatoes under running water and dry thoroughly.
03 - Pierce each potato several times with a fork.
04 - Place potatoes directly on the oven rack or on a baking tray and bake for 55 to 60 minutes until skins are crisp and a fork pierces easily.
05 - Remove potatoes from oven and let rest for 5 minutes.
06 - Slice each potato lengthwise without cutting through completely and gently squeeze to fluff the interior.
07 - Add butter if desired and season with salt and freshly ground black pepper.
08 - Spoon sour cream over each potato and sprinkle with chopped chives. Serve immediately.