Preheat the oven to 350°F. Spray an 8x8-inch pan with non-stick cooking spray.
Place potatoes in a large pot then fill the pot with enough water to cover by 1 inch. Bring to a boil and cook for 20 minutes, or until the potatoes are tender. Drain and return the potatoes to the hot pot.
Into the pot, add cream cheese, sour cream, butter, 2 tablespoons chives, and salt. Using a potato masher, mash everything together until it reaches your desired consistency. Adjust seasoning to taste.
Transfer the potato mixture to an 8x8-inch baking dish. Sprinkle with the remaining 2 tablespoons chives.
Bake, uncovered for 30 minutes until the edges are slightly bubbly, then serve hot.