All you do is sift the flour, baking powder and bicarbonate of soda into a roomy mixing bowl, lifting the sieve quite high to give the flour a good airing as it goes down.
Then simply add all the other ingredients, except the stout. Now, using an electric hand whisk, combine them for about one minute until you have a smooth creamy consistency. Finally stir in the stout, a little at a time, until it’s all incorporated. Next divide the mixture between the two prepared tins and bake near the centre of the oven for about 30–35 minutes.
They are cooked when you press lightly with your little finger and the centre springs back. Then remove them from the oven and after about 30 seconds loosen the edges by sliding a palette knife all round then turn them out onto a wire cooling tray. Carefully peel back the lining by gently pulling it back. Now lightly place the other cooling tray on top and just flip them over so that the tops are facing upwards (this is to prevent them sticking to the cooling tray).
To make the icing: melt the broken chocolate with the stout in a bowl set over a pan containing 5cm of barely simmering water, without the bowl touching the water. When it’s melted (5–10 minutes) take it off the heat. Beat in the butter and leave it to cool a little before beating in the icing sugar with an electric hand whisk.
Now transfer a third of the icing to a separate bowl and stir the chopped walnuts into that. After the icings have cooled to a spreadable consistency, sandwich the cake with the walnut icing, then spread the remaining two thirds of the icing on the top of the cake, using a palette knife.
Finally decorate with a circle of walnut halves. Leave the icing to set completely before storing in an airtight tin.
Pre-heat the oven to 180°C, gas mark 4
Using a fan-assisted oven? Click here
The Delia Online bakeware range is now available online, and you can buy our 20cm Round Sponge Tins with Loose Base and washable and reusable liners direct from Silverwood.