When cool enough to handle, halve the potatoes. Hollow out the skins by scooping out the flesh with a spoon to a bowl but leaving a 1/4-inch thick potato shell. Return the skins flesh-side up to the baking sheet. Add spicy queso dip to the potato flesh and stir to combine. Spoon the filling back into the potato skins. Bake until warm and bubbly, about 15 minutes. Sprinkle with scallions before serving.