Add potatoes to a pot, cover with water, and bring to a boil.
Reduce heat, cover, and simmer for 15 minutes, or until potatoes are tender. Turn the oven on at this time to preheat to 350 degrees Fahrenheit.
Fry bacon in a pan that has been lightly sprayed with non stick spray. Allow to cool on a paper towel lined plate, and chop when cooled.
When the potatoes are done, drain them and place in a large bowl, add the sour cream, butter, salt, and pepper.
Beat on lowest speed, add 2 cups of cheese, bacon, and green onions, stir by hand.
Transfer to a greased baking dish and bake for 30 minutes.