01 - Set the oven temperature to 400°F.
02 - Wash each potato thoroughly under running water and dry completely.
03 - Poke each potato several times with a fork to allow steam to escape during cooking.
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 slides in easily.
05 - Remove from oven and let potatoes rest for 5 minutes.
06 - Cut each potato lengthwise without slicing all the way through. Gently press the ends to fluff the interior.
07 - If using, add a dollop of unsalted butter; season with salt and freshly ground black pepper.
08 - Spoon sour cream generously onto each potato and sprinkle with finely chopped chives. Serve immediately.