Vanilla syrup and passion fruit syrup are both available at specialty stores and from kalustyans.com.
In a medium saucepan, combine 16 ounces water with 2 cups sugar and 6 medium cinnamon sticks. Stir over moderate heat until the sugar is dissolved, then simmer (do not boil) for 10 minutes. Let cool. Remove the cinnamon sticks and pour the syrup into a jar. Refrigerate for up to 2 weeks. Makes about 24 ounces.