Preheat the oven to 400°F (200°C).

Scrub the medium russet potatoes clean, poke holes with a fork, bake for about 45 minutes until tender, then reduce the oven temperature to 350°F (175°C).

In a skillet over low heat, cook the bacon until crispy—about 10 minutes. Drain excess grease, chop it into pieces, and set aside.

Remove the skins from the baked potatoes, mash them until fluffy and smooth.

Combine the mashed potatoes with salted butter, sour cream, and milk until smooth. Fold in half of the crispy bacon.

Spread the creamy potato mixture evenly in a greased 9x13 inch baking dish. Top with shredded cheese and the remaining bacon.

Bake uncovered at 350°F (175°C) for about 25 minutes, or until heated through and the cheese is bubbly.

Let cool for 5 minutes before topping it with sliced green onions.