There are lots of recipes for Coffee Martini, and this Espresso one is very easy to make and super delicious. It requires only three ingredients. You are approaching the end of of a terrific meal. The dessert plates are cleared, then shake a chic Espresso Martini. Why 3 coffee beans? A serving of sambuca  with seven coffee beans, representing the seven hills of Rome. Likewise, a serving with one coffee bean, called con la mosca, which means “with the fly”, is as common. The traditional serving is with three coffee beans, each representing health, happiness and prosperity. wikipedia source.  FYI- I worked in an Italian restaurant for 5 years, and a serving of sambuca was always with 3 coffee beans and lit. Unfortunately, we lost quite a few napkins.