Heat the water and sugar on the stovetop (or in the microwave) until the sugar dissolves. Then pour it into a pitcher along with the lemon juice, Limoncello, lemon zest, and salt. Stir well.
Pour the Limoncello mixture into 10-12 popsicle molds. Then slide one large mint leaf down into each popsicle mold. Place the lid on the mold trays, and slide popsicle sticks down into the lid slots.
Freeze for 4+ hours until solid. Then flip the molds over and run under warm water to release the popsicles.