Start by washing and drying the 4 medium Russet potatoes.
Carefully make slices across each potato, about 1/8 to 1/4 inch apart, making sure not to cut all the way through. A tip is to place chopsticks or wooden spoons on either side of the potato while slicing to prevent the knife from cutting all the way down.
Brush the potatoes generously with melted 4 tablespoons butter, ensuring it gets into the slices. Sprinkle them with g1/2 teaspoon garlic powder, 1 teaspoon kosher salt and 1/2 teaspoon black pepper, again making sure the seasoning gets between the slices.
Preheat your air fryer temperature to 390 degrees F (200°C). Place the potatoes in the air fryer basket and set cook time for 30-40 minutes or until they start to soften and open up.
Remove the potatoes from the air fryer. Insert slices of 8-10 slices cheddar cheese into the cuts of each potato.
Return the potatoes to the air fryer and cook for an additional 5-10 minutes, or until the cheese is melted and bubbly, and the potatoes are cooked through.
Once done, remove the potatoes from the air fryer. Garnish with chopped fresh herbs like 1 teaspoon parsley or 1 teaspoon chives Serve hot, with sour cream if desired.