Heat oven to 400° F. Line 12 medium muffin cups with paper baking cups or spray bottoms only with no-stick cooking spray. For topping, combine oats and sugar; set aside. For muffins, in large bowl combine dry ingredients; mix well. Combine milk, egg whites, oil vanilla and lemon peel; add to dry ingredients and mix just until dry ingredients are moistened. (Batter should be lumpy.) Gently stir in blueberries. Fill muffin cups almost full. Sprinkle with reserved topping, patting gently. Bake 20 to 24 minutes or until light golden brown. Let muffins stand a few minutes; remove from pan. Serve warm.