Prepare the Potatoes: Wash the russet potatoes thoroughly. Poke several holes in each potato using a fork. Drizzle the potatoes with olive oil and sprinkle with salt and pepper.
Air Fry the Potatoes: Place the potatoes in the air fryer basket. Air fry at 400°F (200°C) for 35-40 minutes, or until they are fork-tender and the skin is crispy. Remove the potatoes and allow them to cool for 5-10 minutes.
Cut and Scoop: Once the potatoes are cooled slightly, cut each in half lengthwise. Carefully scoop out most of the potato flesh, leaving a small border of potato along the skin to hold the filling.
Prepare the Filling: In a mixing bowl, mash the scooped-out potato flesh with sour cream, butter, milk, green onions, salt, and pepper until smooth. Stir in ¾ cup cheddar cheese and mix until fully combined.
Refill the Potato Skins: Spoon the mashed potato mixture back into each potato skin, pressing it down gently to fill the skins. Top each potato with the remaining cheddar cheese.
Air Fry Again: Place the filled potatoes back into the air fryer basket. Air fry at 350°F (175°C) for 2-3 minutes, or until the cheese is melted and bubbly.
Optional Toppings: Garnish with chopped bacon and chives, if desired, and serve immediately.