Mocha Syrup:
Whisk together the cocoa powder, coffee, sugar and salt in a medium saucepan. Cook over medium heat and bring to a boil, then reduce to a simmer.
Simmer for a couple minutes, whisking constantly until sugar and cocoa powder are dissolved and mixture is syrupy. Remove from heat and chill. You'll have enough syrup for several ice cream sodas.
Fill glass about 3/4 full and top with 2-3 scoops of gelato and top with a little more club soda. Top with whipped cream, a couple chocolate espresso beans and a maraschino cherry if desired.