In a medium sauce pan stir together raspberries, sugar and water. Cook over medium heat until raspberries are mashed down and mixture is bubbling. Continue to cook until thick and syrupy, stirring often, approximately 10 minutes. Strain using a fine mesh sieve, pressing solids against the sides to expel as much juice as possible. Discard solids and stir reduced balsamic vinegar and 1/2tsp vanilla into raspberry juice. Cool until chilled.