Freeze the banana nectar in the ice cube tray for at least 4 hours. Drain the morello cherries, collecting the juice. Poke 6 morello cherries on a plastic skewer or wooden skewer.
Place the skewers in tall glasses (300 ml each). Mix cherry nectar, morello juice and mineral water in large measuring cups. Just before serving, add the banana ice cubes to the glasses and add the cherry spritzer.