Baked Yorkshire rhubarb, financiers and crème pâtissière

By Shauna Froydenlund From Saturday Kitchen Ingredients For the crème pâtissière 300ml/10fl oz full-fat milk 50g/1¾oz fresh root ginger, peeled and grated 1 vanilla pod, split and seeds scraped 4g agar-agar 4 free-range egg yolks 50g/1¾oz caster sugar 20g/¾oz custard powder 100ml/3½fl oz double …