1. Freeze 2 ice-cube trays, 1 with pineapple juice, and 1 with orange juice; in a blender, blend until smooth the yogurt, banana, honey and cinnamon; transfer to a measuring cup and set aside; rinse the blender jar.
2. Blend remaining pineapple juice and pineapple ice cubes until smooth; divide among four glasses; top with the yogurt mixture and place in freezer.
3. Blend the orange ice cubes and orange juice until smooth; top each glass with the orange slush; garnish with a sprinkling of cinnamon and an orange slice; serve immediately.