Place prunes with water to cover in a small saucepan; let stand 30 minutes, and drain. Return prunes to saucepan with water to cover. Add lemon slices and cinnamon; bring to a boil. Reduce heat; cover and cook 20 minutes or until prunes begin to swell. Add sugar, and continue cooking 10 minutes.
Remove prunes; place in a 1- quart serving bowl, and set aside. Continue cooking juice 15 minutes or until thickened. Pour over reserved prunes, discarding lemon slices and cinnamon sticks. Cover and chill thoroughly. Spoon into individual serving dishes, and serve cold.