Preheat oven to 425 F. Grease a 12 muffin (2 1/2") tin. Combine mix and sweetener equivalent to 1/4 cup sugar in bowl; add yogurt. Add egg; beat with fork until well combined. Fold berries gently into batter with rubber spatula; place about 1/4 cup batter into each muffin cup. Combine lemon peel and remaining sweetener and mix well.
Yields 12 muffins.
NOTE: Lower fat content by using Low Fat Bisquick, and egg substitute in place of the whole egg. No nutritional information available on this recipe. (Trish)