Add the tequila, Cointreau, lime juice and prickly pear syrup in a cocktail shaker.
Shake well to combine.
Pour the salt onto a small plate or bowl.
Rim the edge a margarita glass with a slice of lime to moisten and dip into salt.
Pour the margarita into glass over ice.
Garnish with a lime slice and pineapple leaves.
Notes
Prickly Pear Margaritas are best served after shaking. Prickly Pear Syrup can be made up to 3 weeks in advance and stored in an airtight container at room temperature.