Add the passionfruit, lime juice, and agave to a blender and blend until smooth.
Optional: Use one of the squeezed limes and drag it around the rim of two glasses. Dip the rim in sugar for a sugar lined rim.
Divide the ice between each cup. Add half of the passionfruit mixture to each cup. Add the sparkling water (divided between the two glasses).
Optional: top with fresh rosemary.
Enjoy!