Chocolate porter cake

Method

1. Heat the oven to 180°C/160°C fan/ gas 4. Grease a deep 23cm loose- bottomed cake tin and line with baking paper. In a large pan, gently warm the porter, butter and chocolate until the butter and chocolate have melted.
2. Mix the cocoa powder and sugars in a large bowl, rubbing away lumps. Pour in the chocolate mixture gradually, whisking well using a balloon whisk, then add the eggs. Whisk until it’s thick and smooth, then whisk in the yogurt, vanilla, flour and bicarbonate of soda.
3. Pour the batter into the lined tin and bake for 1 hour or until a skewer comes out clean. Leave for 5 minutes, then turn out onto a wire rack to cool.
4. Meanwhile, in a large bowl, beat the topping ingredients with an electric mixer until the mix just holds its shape. It’s important not to carry on beating as the topping will go runny – and the more you beat, the runnier it will get. Beware, too, that adding more icing sugar isn’t a quick fix – it will only make the topping runnier. Swirl the icing on top of the cooled cake.