Preheat oven to 350ºF.
Peel and cut Russett potatoes into bite-size chunks. Place in a large saucepan, cover completely with water, and place on medium-high heat. Cook until boiling. Turn off. Drain.
Place cooked potatoes in a 9 x 13 baking dish, in a single layer. Allow potatoes to cool for 20 minutes.
Scatter the pads of butter throughout the dish, on top of the potatoes.
Pour the ranch dressing on top of the potatoes in row formation.
Spread salt and pepper over the potatoes.
Distribute the shredded cheddar cheese on top of the potatoes.
Sprinkle the bacon bits on top of the potatoes.
Place in the oven for 15 - 20 minutes or until cheese is bubbly.
Remove from the oven. Allow to rest for 5 minutes. Garnish with scallions and serve.