Manon Lagrève’s carrot cake

Method

1. Heat the oven to 180°C fan/gas 6 and grease and dust the cake tins with butter and flour.
2. Combine the flour, baking powder, both sugars, cinnamon, mixed spice and a large pinch of salt in a large bowl. Add the chopped walnuts (if using).
3. In a separate bowl, combine the vegetable oil, eggs and vanilla, then add to the first bowl. Whisk well until you get a uniform batter. Finish by adding the carrots and use a spatula to fold them in. Divide the batter between the tins and bake for 35-45 minutes until a skewer inserted in the middle comes out clean. Turn upside down on a cooling rack, remove the tin and allow to cool completely.
4. Meanwhile, make the icing. Whip the butter for 2 minutes using an electric whisk, then add half the icing sugar and whisk for another 2 minutes. Whisk in the cream cheese and vanilla, then add the remaining icing sugar and whisk for another couple of minutes.
5. Slice the top of one cake with a serrated knife; hold the knife flat and work around the cake to create an even and flat sponge. Use a spatula and spread a 5mm layer of icing on top of the first sponge. Put the second sponge on top, then spread the rest of the icing on top of the cake (if you have made 3 smaller sponges, divide the icing evenly among the layers).