1. Preheat the oven to 375°F and grease a 9×13-inch baking dish.

2. Wash, peel, and dice the potatoes into evenly sized pieces.

3. In a large mixing bowl, stir together the sour cream, mayonnaise, cheddar cheese, garlic powder, onion powder, salt, and black pepper until creamy.

4. Add the diced potatoes, most of the crumbled bacon, and part of the sliced green onions to the bowl, then toss until everything is well coated.

5. Spread the mixture evenly into the prepared baking dish.

6. Dot the top with butter and sprinkle on a little extra cheese if desired.

7. Bake for 50 to 60 minutes, or until the potatoes are tender and the top is golden and bubbling.

8. Remove from the oven, top with the remaining bacon and green onions, and serve warm.