Reduce oven temperature to 350ºF. Cut small slice off both ends of each potato. Cut potatoes crosswise in half. Scoop out centers, leaving 1/8-inch-thick shells. Place potato flesh in medium bowl; mash. Squeeze garlic out of papery shell into bowl with potatoes. Add sour cream, 3/4 of the VELVEETA and Parmesan; beat until fluffy. Spoon into shells, mounding filling as necessary; place in shallow baking dish.