Preheat the oven to 400℉.
Then, wash and dice the Yukon potatoes up. You do not need to soak them or anything.
In a bowl, mix together the milk and the ranch dressing. Then, add the diced potatoes to the baking dish and pour over the sauce. Give it a little mix to make sure that the dry potatoes aren't touching the bottom of the dish.
Cover the baking dish with foil and place in preheated oven for 30 minutes.
While that's cooking make and chop up your bacon.
At 30 minutes, remove the dish and the foil. Top with shredded cheese and bacon. Now, bake a remaining 25 minutes or so in the oven. You want the cheese melted and browning a little bit.
Lastly, remove from oven and allow the potatoes to cool because the sauce will be extremely hot.