The Vatican has given its blessing to a shortbread milkshake.

Part of the proceeds from sales of "#PopeinPhilly" milkshakes will benefit a world gathering of Catholic families and the pope's visit to Philadelphia in the fall.

Archbishop Vincenzo Paglia picked the winning flavor from three choices during a visit Monday to a Potbelly Sandwich Shop. The president of the Vatican department that organizes the world meetings, Paglia got help from a dozen Catholic school students.

The shake features a blend of vanilla ice cream and shortbread cookies.

Pope Francis will attend the closing event of the world meeting on Sept. 26. The next day he'll celebrate an outdoor Mass.

Fifty cents from every shake sold at three locations in Philadelphia will benefit planning for the events.

The pope also will visit New York and Washington, D.C.