Preheat and prep: Heat oven to 425°F (220°C).
Prick potatoes with a fork, rub with a little oil and salt, and place on a baking sheet.
Bake potatoes: Bake 50–60 minutes, until skins are crisp and a fork slides in easily. Let cool until safe to handle.
Cook bacon: While potatoes bake, cook bacon until crisp. Drain on paper towels and crumble.
Scoop and mash: Reduce oven to 350°F (175°C).
Slice potatoes and scoop out the fluffy insides into a large bowl. Discard or save skins for snacking.
Add the creamy base: Add cream cheese, sour cream, melted butter, garlic powder, onion powder, salt, and pepper. Mash lightly until mostly smooth with a few small chunks.
Adjust consistency: Stir in warm milk a little at a time until creamy but thick enough to hold shape.
Taste and adjust salt and pepper.
Fold in the good stuff: Mix in 1½ cups cheddar, half the bacon, and half the green onions.
Assemble: Spread into a greased 9x13-inch baking dish. Top with remaining cheddar and bacon.
Bake: Bake 20–25 minutes until heated through and cheese is melted. Broil 1–2 minutes if you want extra golden bubbles.
Finish and serve: Sprinkle with remaining green onions.
Serve hot with a dollop of sour cream or a dash of hot sauce if you like.