Triple-Citrus Granita with Passion Fruit

Zest and juice lemons, limes, and 2 oranges. In medium saucepan, stir 1 1/2 cups water with sugar over high until sugar dissolves. Transfer to 9-by-13-inch glass baking dish. Let cool. Mix in 1 2/3 cups of citrus juices and 1 tbsp. each of lemon, lime, and orange zests. Freeze until icy, about 2 hours. Transfer to food processor. Pulse granita until slushy. Refreeze until icy, about 45 minutes. Cut peel and white pith from remaining 3 oranges. Slice oranges into rounds; divide among bowls. Scrape granita with fork until icy. Top oranges with granita. Scoop passion fruit pulp on top.