Add limoncello, rum, and cucumbers to cocktail shaker. Muddle cucumber well. Shake and strain over ice. Top with club soda and stir gently. Garnish with cucumber slice and lemon twist.

Want to try to make limoncello at home

A well-stocked liquor store near you may have limoncello, but traditionally you should make it at home. You'll first want to use a vegetable peeler to remove the zest (just the yellow part) from the pith (the bitter white part) of 8 lemons. Pour one liter of 100 proof vodka or grain alcohol over the zest in an airtight bottle or jar and let steep 7-10 days. Strain the solids out using a fine strainer or cheesecloth and add 3 cups simple syrup (3 cups water and 3 cups sugar, boiled until sugar dissolves). Ta-da!