Passion fruit puree—the key ingredient in this take on a Brazilian classic—can be found in the freezer section of most grocery stores. Slideshow: More Rum Drink Recipes
Place the lime pieces and sugar in a large cocktail shaker and muddle until the sugar has dissolved, about 2 minutes. Add enough ice to the shaker to fill it, then pour in the passion fruit puree and cachaça. Stir with a bar spoon for 1 minute, then divide between 2 glasses and serve.