Boil the potatoes: Peel and cut potatoes into even chunks. Boil in salted water until tender, about 15–20 minutes.
Mash the potatoes: Drain well, then mash until smooth using a potato masher or ricer.
Mix in the goodness: Add cream cheese, sour cream, half of the butter, garlic powder, paprika, salt, and black pepper. Stir until fully combined and creamy.
Assemble for baking: Spread the mixture into a greased 9x13-inch baking dish.
Top and bake: Drizzle with the remaining butter and sprinkle lightly with paprika. Bake at 375°F (190°C) for 40 minutes, until golden and heated through.
Garnish and serve: Sprinkle chopped green onions over the top and serve warm.