For nearly 70 years, workers minted Frango chocolates on the 13th floor of the Marshall Field & Co. building on State Street. Frango production moved out of state in 1999 to the dismay of civic leaders and local mint chocolate aficionados. The Frangos are long gone, but more than two decades later, chocolate has made its return to the upper floors of the building now anchored by the Macy’s ...