Prepare Baked Potatoes in Instant Pot or in Oven. To Bake Potatoes in Oven, place scrubbed potatoes on aluminum foil. Drizzle with olive oil and sprinkle with 1 teaspoon salt. Roll potato to coat with salt and oil and then wrap in the foil. Place on a baking sheet and bake at 400 degrees, until potatoes are fork-tender–about 45 minutes.
Once potatoes have been baked, slice potatoes in half. Using a spoon, melon baller, or cookie scoop, scoop out the flesh of the potato, leaving 1/4-1/2 inch border around potato skins.
Place the flesh of potato in bowl and mash well with a fork. Add in warm butter, milk, and salt and mix well to incorporate. Stir in sour cream and shredded cheese into potato filling.
Place half the potato skins onto a baking sheet. Sprinkle potato skins with salt and pepper. Generously fill the stuffing into the potato skins and top with additional cheddar cheese.
Return stuffed potatoes back to the oven and bake for 15 minutes, until cheese is melted and filling is warmed through.
**I like to stuff these double stuffed potatoes so that they are heaping full of the stuffing. If you would like to JUST stuff your potatoes, you will need to fill all 8 potato skins.