Preheat the oven to 450°F. Clean and scrub the potatoes removing any blemishes. Rub all over with olive oil and sprinkle on all sides with 2 teaspoons salt and black pepper.
Pierce the top of each potato several times with a knife and place onto a sheet pan. Bake for 60-75 minutes or until a knife easily glides thru the middle. Lower the oven temperature to 350°F.
Cook bacon in a large skillet over medium-high heat until crisp. Remove from the pan to a paper towel-lined plate to drain. Chop or crumble, then set aside.
Cut the potatoes in half lengthwise and place into a large mixing bowl. Use a potato masher to mash the potatoes leaving them "chunky" not completely smooth.
To the bowl add sour cream, half and half, 1/2 cup melted butter, dry ranch seasoning mix, garlic salt, granulated garlic, onion powder and black pepper.
Mix to fully combine then add bacon, 2 cups shredded cheese and green onions. Mix to evenly distribute. (Reserve some bacon to garnish after baking.)
Spray a 13x9-inch baking dish with cooking spray. Pour the potato mixture into the dish. Top with the remaining 1 cup shredded cheese and 3 Tbsp of sliced butter to dot the top.
Place into the 350°F oven and bake for 35-45 minutes or until golden and bubbly.
Garnish the top with reserved bacon and chives and serve.