Scratch Cupcakery in West Des Moines is one of 50 bakeries across the U.S. partnering with Facebook on May 10 to launch a new feature called Birthday Stories on the social media platform. From 9:30 a.m. until supplies last, visitors at the West Des Moines shop will receive a free cupcake to celebrate the launch. The new feature will allow users to create “digital birthday cards” out of photos and videos on Facebook, according to a press release.