Classic rice sponge

Whip the egg whites with the starch and the caster sugar; pour in the lightly beaten yolks in a thin stream, add the vanilla seeds scraped from the pod and finally the rice flour. Fold gently from the bottom up. Spread on a baking tray lined with baking paper and bake at 240 °C for 8 minutes. For the chocolate version, add 40 g of unsweetened cocoa powder in place of the rice starch.