plain flour, for dusting
125g/4陆 oz caster sugar
30g/1oz cornflour
icing sugar, for dusting
1 vanilla pod, split, seeds scraped out
butter, for greasing
225ml/8fl oz double cream
3 free-range egg yolks
175ml/6fl oz full-fat milk
300g/10陆 oz ready-rolled puff pastry