1. In a medium saucepan combine [[cream]], syrup, [[water]] and [[cocoa|cocoa powder]]. Bring to a boil over medium heat. Reduce heat to low; cook, stirring occasionally, 5 minutes. Remove from heat and stir in [[vanilla]].
2. Pour mixture into two [[ice]] cube trays. Freeze 2 hours.
3. Before serving transfer cubes into a food processor. Process until mixture is finely chopped and slushy.