Split potatoes horizontally and scoop out pulp. Mash pulp, yogurt and Country Crock® Calcium plus Vitamin D in medium bowl. Stir in 1/4 cup cheese, ham and salt. Evenly fill potato halves with potato mixture. Arrange on baking sheet, then sprinkle with remaining cheese. Bake 15 minutes or until heated through. Garnish, if desired, with chopped chives and serve with additional Spread.