Pour the cranberry juice into a shallow freezerproof container and freeze for about 2 hours or until a thick layer of ice crystal has formed around the edges.
Mash the semi-frozen juice with a fork to break up the ice, then return the mixture to the freezer for a further 2-3 hours or until it is almost solid.
Pour the apple juice into a small pan, add two cinnamon sticks and bring to just below boiling point. Pour into a jug(pitcher) and leave to cool, then remove the cinnamon sticks and set them aside. Cool then chill the juice.
Spoon the cranberry juice into a food processor or blender. Add the cinnamon-flavored apple juice and process briefly until slushy. Pile the mixture into cocktail glasses, top up with chilled ginger ale, decorate with cinnamon sticks and serve immediately.