Combine apple juice and apricots in a microwave-safe bowl. Cover with heavy-duty plastic wrap, and vent. Microwave at high 3 minutes or until apricot mixture boils. Let stand, covered; cool completely. Drain apricots in a colander over a bowl, reserving apple juice.
Lightly spoon flour into dry measuring cups, and level with a knife. Combine the flour and the next 5 ingredients (flour through nutmeg) in a medium bowl, and make a well in center of mixture. Combine 3 tablespoons reserved apple juice, margarine, vanilla, egg whites, and yogurt; stir well with a whisk. Add to flour mixture, stirring just until moist. Stir in reserved apricots.
Spoon batter into 12 muffin cups coated with cooking spray. Bake at 400° for 20 minutes or until muffins spring back when touched lightly in center. Remove muffins from pans immediately; place on a wire rack. Dip muffin tops in remaining apple juice; sprinkle each with 1/2 teaspoon sugar.