Place the potatoes in a pot and cover with water; bring to a boil.

Cook until fork tender; about 20 minutes.

Drain the potatoes and return them to the pot.

Using a potato masher, mash the potatoes. It's okay to have lumps.

Add the melted butter, sour cream, milk, cheddar cheese and bacon.

Stir until well combined.

Place the potato mixture into a casserole dish that's been coated with non-stick cooking spray.

Sprinkle the additional ½ cup of cheddar cheese on top.

Bake in a preheated 385 degree oven for 20 minutes or until hot and the cheese is bubbly.