And the rest of the recipe...!

Grate the carrot straight into a mixing bowl, then sift in the dry ingredients to give them a good airing and tip any grains left behind in the sieve into the bowl too. Add all the rest of the cake ingredients and stir well until everything is well and truly mixed, then scrape the mixture into your prepared tin.Bake the cake in the centre of the oven for 1 hour, or until well risen. When cooked it will come about two-thirds of the way up the tin and just begin to shrink away from the sides of the tin. After that remove it from the oven and leave the tin on a wire rack to cool for 5 minutes before turning the cake out and stripping off the paper.When it has cooled for 45 minutes or so, you can spread the topping on. To make the topping, combine the ingredients in a small bowl and beat until smooth. Spread it thickly on the top of the cake and decorate it, perhaps with additional walnut pieces. Store in an airtight tin or container.