One of Chicago's most beloved deep-dish pizza restaurants is marking its 50th anniversary by bringing back the original 1976 recipe for a limited run. The vintage version features a buttercrust base, a thicker layer of mozzarella, and the restaurant's now-discontinued spicy Italian sausage blend.

Lines stretched around the block on opening day of the anniversary celebration, with some fans traveling from out of state to taste the throwback pie. The owners say the original recipe will be available through the end of May before returning to their modern menu.