Sprinkles, the “world’s first cupcake bakery,” is launching a National Cupcake Day promotion on Friday, December 1 giving away free cupcakes for a year* to one lucky customer in each of its 24 bakeries nationwide. Winners will be contacted on December 14 in time for National Cupcake Day on December 15.  To enter, customers must be a member or sign up for the Sprinkles Perks Program and must make a purchase at any Sprinkles bakery from December 1-12. Each in-bakery purchase will count as a different entry, so guests have plenty…