Combine berries, water, sugar, and cinnamon in medium saucepan and bring to boil; reduce heat and cook until berries are soft. Discard cinnamon stick. Mix cornstarch and water and add to berry mixture. Bring back to boil and stir until clear. Cover and chill. Serve in small bowls with spoonful of sour cream if desired. Variation: Add 1/2 cup of Burgundy wine before chilling.