Tip: I suppose that the alcohol could be omitted for a sort of Shirley Temple cocktail, though I think the rum, especially coconut-flavored rum, adds a lot of oomph to the drink.
2/3 to 3/4 cup very well-chilled orange juice
2 to 3 tablespoons light rum, coconut flavored rum, or tequila, as desired
1 tablespoon fresh lime juice
1 1/2 to 2 tablespoons well-chilled prickly pear cactus syrup or grenadine syrup
A seeded orange wedge for garnish
Shake the orange juice, rum, lime juice, and several ice cubes in a cocktail shaker, or stir together in a cup. Strain into a well-chilled stemmed goblet or wine glass. Gently pour the cactus syrup into the glass; do not stir. The syrup will sink to the bottom, producing a layered “sunset” look.
Cut a notch in the orange wedge and hook it on the rim of the glass. Serve immediately.