Preheat the oven to 425°F (220°C). Scrub the russet potatoes under cold running water to remove dirt, then pat dry with a towel. Use a fork to pierce each potato 6–8 times all over to allow steam to escape during baking.

Oil and season

Rub each potato with olive oil until the skin is lightly coated. Sprinkle the kosher salt and black pepper evenly over the skins, rubbing gently so they adhere.

Bake

Place the potatoes directly on the oven rack or on a rimmed baking sheet if you prefer. Bake at 425°F (220°C) for 45–60 minutes, depending on size. Potatoes are done when an instant-read thermometer inserted into the center reads 205–210°F (96–99°C) or a knife slides in with little resistance.

Rest

Remove potatoes from the oven and let rest 5 minutes. This allows steam to redistribute and makes them easier to handle.

Open and fluff

Using a paring knife, make a lengthwise slit across the top of each potato. Gently press the ends toward the middle to open and fluff the interior with a fork. Season the flesh lightly with a pinch of salt and pepper if desired.

Toppings (optional)

Prepare butter and sour cream

Divide the 4 tablespoons of unsalted butter among the 4 hot potatoes so it melts into the flesh. Spoon about 3 tablespoons of sour cream onto each potato (adjust to taste).

Add cheese and bacon

Sprinkle about 1/4 cup shredded cheddar over each potato so it melts from the residual heat. Scatter chopped crisped bacon evenly across the potatoes.

Finish and serve

Top each potato with sliced chives and season the toppings with the remaining salt and black pepper as needed. Serve immediately while hot.