Fresh after filing for that $100 million IPO, Shake Shack has announced a brand-new burger, too. The ShackMeister Burger — which debuted at a recent food festival — is a classic Shack Angus-beef cheeseburger topped with crispy marinated shallots and, of course, ShackSauce. A single will run you $6.19 and a double goes for $8.99. Starting on January 1, it will be available at all U.S. locations (except the JFK outposts), but only for a limited time. Even if it’s not available all year, 2015 is already shaping up to look very good for the Shack.