Coffee and walnut cake

Method

1. Heat the oven to 180°C/160°C fan/gas 4. Grease and line the base of a 20cm loose-bottomed cake tin with baking paper. For the cake mix, put the walnuts, brown sugar, baking powder, salt and plain flour in a mixing bowl and mix well with a metal spoon or balloon whisk.
2. Make a well in the centre and add the vegetable oil, espresso and beaten eggs, then mix thoroughly until you have a smooth batter.
3. Spoon the mix into the lined cake tin and bake for about 60 minutes, or until a skewer pushed into the centre comes out clean. Cover the top loosely with foil after 40 minutes if it’s getting too brown. Once cooked, take out of the oven and put on a wire rack to cool for 10 minutes. Carefully remove from the cake tin and leave to cool completely on the rack.
4. While the cake is cooling, make the icing. Find a large heatproof mixing bowl that sits snugly on top of a medium saucepan to make a double boiler. Fill the pan halfway up with boiling water, making sure it doesn’t touch the bowl. Bring the water back to the boil, then reduce to a gentle simmer.
5. Put the egg and caster sugar in the mixing bowl and sit on top of the pan. Using an electric mixer, beat the sugar and egg until thick and pale in colour – about 5 minutes. The beaters should leave a trail of mixture when lifted.
6. Whisk in the softened butter a little at a time, then add the cream cheese, coffee extract and liquid espresso. Sift in the icing sugar, then whisk it in at a lower speed until smooth. Cool and chill the icing for 2 hours, so it firms up.
7. Once the sponge has cooled, cut it in half through the centre, using a serrated knife or a piece of thread. Spread a third of the icing on the bottom half of the sponge. Sandwich with the top half, then spread the rest of the icing all over the cake. Decorate with the extra chopped walnuts.