5.Grease with butter a rectangular baking tin - I used a 24 cm square tin, the traditional one is 30 x 20 cm - and scrape the batter into the pan. Use a spatula to smooth the surface.
6.Let rise in a warm place until tripled in volume. I've put it back into the oven with the light on for about 3 hours.
7.Preheat oven to 170°C, fan assisted (take care to remove the cake previously) for 25 - 30 minutes until hazel brown on surface. Take out of oven, remove from the tin let it cool completely on a wire rack. Serve generously dusted with icing sugar.