Preheat oven to 350°. Line two 12-cup muffin pans with cupcake liners; set aside.
Beat cake mix, Hellmann's® or Best Foods® Real Mayonnaise, water and eggs in large bowl with electric mixer on low speed 30 seconds. Beat on medium speed, scraping sides occasionally, 2 minutes. Evenly pour into prepared pans.
Bake 18 minutes or until toothpick inserted in centers comes out clean. Cool 10 minutes on wire racks; remove from pans and cool completely.
Meanwhile, whisk peanut butter, marshmallow creme and whipped topping in medium bowl. Frost cupcakes with peanut butter frosting. Decorate, if desired, with chocolate sprinkles or other cake decorations.