1Heat oven to 350°F (325°F for dark or nonstick pans). Place paper baking cup in each of 24 regular-size muffin cups. Make cake mix as directed on box, using water, oil and egg whites. Divide batter evenly among muffin cups. Bake and cool as directed on box for cupcakes.
2Spoon lemon curd into decorating bag fitted with 1/4-inch round tip. Insert tip into center of each cupcake, no more than two-thirds of the way down; gently squeeze bag, pulling upward until filling comes to top of cupcake. (Do not let filling spill out of cupcake.)
3In medium bowl, mix powdered sugar, lemon peel, lemon juice and milk with spoon until smooth. Dip top of each cupcake in lemon glaze; twist to allow excess to drip off. Smooth top with spatula. Sprinkle with lemon drops.