Pierce the potatoes with a fork and microwave 8 minutes, or until cooked through (cooking time will depend on your microwave and the size of your potatoes). Let cool.
Heat oven to 450ºF.
Cut the potatoes in half and use a small spoon to scoop out the insides, leaving a 1/4-inch rim around the edge. Reserve the potato for another use. Arrange the potato skins cut side up on a heavy baking sheet. Brush the insides with blue cheese dressing. Bake 10 minutes; flip the potatoes so the cut side is down and bake another 10 minutes.
Turn the potatoes over so the cut side it up. Sprinkle with hot sauce and fill with shredded cheese. Bake 5 minutes or until cheese is melted.
Top with scallions. Serve with additional blue cheese dressing and hot sauce, if desired.