Place potatoes in a lightly greased aluminum foil-lined 15- x 10-inch jellyroll pan. Bake at 400° for 1 hour or until tender; cool 30 minutes.
Cut each potato in half lengthwise; carefully scoop out pulp into a large bowl, leaving a 1/4-inch-thick shell.
Beat pulp and next 8 ingredients at medium speed with an electric mixer until blended; spoon into shells.
Bake at 350° for 20 minutes. Serve with desired toppings.