1/2 cup ice cubes, or as needed
1 (1.5 fluid ounce) jigger tequila
1/2 (1.5 fluid ounce) jigger Puerto Rican rum
1/2 (1.5 fluid ounce) jigger coffee-flavored liqueur (such as Kahlua®)
Fill a cocktail shaker with ice; add tequila, rum, and coffee-flavored liqueur. Cover shaker, shake, and strain cocktail into a glass.