Cut a passion fruit in half and scoop out the pulp.

Strain the pulp through a fine mesh sieve to separate the seeds and get about 1/2 oz of puree.

In a cocktail shaker, combine the 2 oz of white rum, 1/2 oz of passion fruit puree, 1/4 oz of lime juice, and 1/2 oz of simple syrup.

Fill the shaker with ice, covering the liquid.

Shake vigorously for about 15-20 seconds, allowing the mixture to chill and mix thoroughly.

Strain the mixture into a chilled cocktail glass.

Optionally, you can garnish with a slice of lime or a small scoop of passion fruit pulp on top for an extra touch of flavor and decoration.