• 1 1/2 cups sugar , divided
• 1 tsp. ground cardamom , plus more for garnish
• 1/2 tsp. ground anise
• Zest of 1 lime (about 1 Tbsp.)
• Juice of 1 lime (about 2 Tbsp.)
• 7 ripe red plums , quartered
• 3/4 cup Greek yogurt
• 1/4 cup rose water or syrup (optional)

Whisk together 1 1/4 cups sugar, cardamom, anise, and lime zest in a medium bowl. Add lime juice and plums; mix well to combine. Let marinate 15 minutes.

In a medium saucepan over medium-high heat, cook plum mixture and 1/2 cup water, uncovered, until plums are soft, about 18 minutes. Remove from heat and let cool slightly, about 10 minutes. Transfer a third of the soup to a blender and puree until smooth; return to pot. Cover and refrigerate until chilled, about 1 hour.

To serve: Stir together remaining 1/4 cup sugar and yogurt. Place a dollop of yogurt in 4 bowls. Spoon soup over yogurt and drizzle each serving with 1 tablespoon rose water or syrup. Garnish with cardamom.