Cut an opening in the top and scoop out the flesh. Add sour cream, milk, butter, salt, pepper and half of the cheese. Stir in the scallions and bacon. Mix well and spoon back into the potato shells. Top with remaining cheese. Bake for another 15 minutes.
NOTE: These potatoes also freeze well and can go straight from the freezer to grill wrapped in aluminum foil on the bottom half of the potato or in the oven for an hour.