Bake in 350° oven for 1 hour or until done.
Depending on size they may take longer.
Meanwhile, fry bacon in skillet over low to medium heat; drain on paper towels.
Crumble bacon into small pieces; set aside.
Cut slice from top of each potato.
Scoop out inside being careful not to break shell.
In mixing bowl, beat together potatoes, cheese, butter, salt and pepper with an electric mixer until fluffy.
Fold in cooked, crumbled bacon.
Pile mixture into potato shells.
Bake in 350° oven for 25-30 minutes.
Top with additional cheese and bacon, if desired.
Bake about 10 minutes longer, until cheese melts.
Garnish with green onions and sour cream, if desired.