0.5 oz. fresh grapefruit juice
0.5 oz. Maraschino liqueur
Add the rum, liqueur, and juices to a cocktail shaker.
Add enough ice to fill the shaker about 1/2.
Top and shake until the shaker is ice cold to touch.
Strain into a pre-chilled coupe.
Spritz with lime oils and drop in the rind, serve.