The Brooklyn martini is named after one of the five Boroughs of New York. It is less known than its neighbour, the Manhattan, but it is equally delicious. The recipe calls for Amer Picon a French bitters apéritif. It is not  a very common ingredient, so I suggest a substitute such as an amaro like Ramazotti, Nonino, or Montenegro. The end result is a strong, complex and smooth cocktail.