Boil potatoes until tender. Drain and mash with sour cream, cream cheese, 4 tablespoons of the butter. Add onion and salt, mix well Spread in a 13 x 9 pan, drizzle remaining two tablespoons butter, melted over the top Sprinkle with paprika Bake covered at 350 for 40 mins Uncover and bake 20 mins more until bubbly