Heat oven to 400°F. Spray bottoms only of 12 muffin cups with nonstick cooking spray.
In small bowl, combine yogurt, oil, lemon juice and egg whites; blend well. Set aside.
Lightly spoon flour into measuring cup; level off. In medium bowl, combine flour, 3/4 cup sugar, baking powder, lemon peel and salt; mix well. Stir in frozen raspberries.
Add yogurt mixture to flour mixture; stir just until dry ingredients are moistened. Spoon batter evenly into sprayed muffin cups. Sprinkle each with 1/2 teaspoon sugar.
Bake at 400°F. for 16 to 20 minutes or until tops are golden brown and toothpick inserted in center comes out clean. Immediately remove from pan. Serve warm.