Cut the pears in half and scoop out the core with a small spoon or cut out with a small sharp knife (this will partly depend on how ripe they are).
Drop the vanilla into the apple juice and then pour this over the pears. Sprinkle over 1 tbsp of the sugar and roast for 30 mins. Spoon the juices over the pears at least once during cooking.
Sprinkle the remaining sugar over the top of the pears and dot with the butter. Return to the oven for another 10 mins or until the pears are tender and slightly caramelised.
Serve with the yogurt. If serving to toddlers, you might like to cut some pear into small pieces or mash before mixing with a little yogurt.
Cook's tip: for babies, purée or finely chop.