Wash the rice well under cold running water and drain.
Place the milk in a heavy-based saucepan. Bring to boiling point and pour in the rice in a stream. Cover and cook gently for around 25 minutes.
Stir in the caster sugar and vanilla sugar and mix well. Cover and cook for a further 5 minutes or so.
Divide the rice among small bowls, allow to cool, then refrigerate.
Drizzle some liquid caramel over each bowl just before serving.