1. 1 In a blender, combine ½ cup Simple Syrup (recipe follows), ¼ cup lime juice and 2 cups peeled and chopped cantaloupe. Process until smooth and turn out into a large pitcher. Stir in 3 cups cold water.
2. 2 Cut 4 ripe passion fruit in half, scoop out pulp and seeds and add to the cantaloupe mixture. Stir and chill; discard fruit skins.
3. 3 When ready to serve, fill tall glasses with ice, pour two-thirds full with the agua fresca and top with cold cava or Prosecco. Garnish with a wedge of cantaloupe, if desired.

Simple Syrup

1. Combine water and sugar in a small saucepan. Bring to a simmer over medium heat and stir until sugar is dissolved. Let cool to room temperature. Simple syrup will keep in the fridge for two weeks in an airtight container.