Preheat your oven to 200°C/gas 6.
Peel, quarter and core the pears.
Put the sugar into a 20cm ovenproof frying pan to melt over a low heat without stirring.
Once the sugar has turned a caramel colour, stir in the butter to make a smooth caramel.
Add the vanilla seeds, star anise and cinnamon stick to the pan.