There's no rule that says warm-weather cocktails must be served with tiny umbrellas. We updated this tiki-bar fave of simple syrup, gin, and sparkling wine with an unexpected garnish, a sprinkling of fruit seeds.
Combine sugar and water in a small saucepan. Bring to a simmer over medium heat, stirring until sugar is dissolved. Remove from heat; let syrup cool in refrigerator.
To assemble cocktail, pour 1/2 teaspoon simple syrup, gin, and passion fruit seeds and juice into an old-fashioned coupe or Champagne glass. Top off with sparkling wine; serve immediately. Reserve extra simple syrup for additional cocktails.