This Peanut Butter Chocolate Cake is pure decadence! Rich chocolatey layers and a silky peanut butter frosting.
- 200g/7oz unsalted butter, plus extra for greasing
- 250ml/9fl oz hot water from a just-boiled kettle
- 50g/1¾oz cocoa powder
- 100g/3½oz soft dark brown sugar
- 125g/4½oz caster sugar
- 2 tsp vanilla extract
- 225g/8oz plain flour
- 1 tsp baking powder
- ½ tsp bicarbonate of soda
- 2 large free-range eggs, at room temperature
For the icing
- 600g/1lb 5oz icing sugar
- 300g/10½oz unsalted butter, softened
- 400g/14oz smooth peanut butter (the regular kind, not a health-store variety)
- 2 tsp vanilla extract
- ½ tsp fine sea salt
- 120ml/4fl oz double cream
- 30g/1oz dry roasted peanuts, chopped, to decorate
- Preheat the oven to 180C/160C Fan/Gas 4. Grease 4 x 20cm/8in ultra-shallow layer cake tins and line them with baking paper. Don’t use loose-bottomed tins as this is a runny batter.
- Cut the butter lengthways into four pieces (just to aid melting), place in a heavy-based, fairly wide saucepan and set over a gentle heat. Add the just-boiled water and whisk in the cocoa and the sugars. Whisk gently until the butter has melted and you have a smooth, amalgamated mixture. Remove from the heat and stir in the vanilla. Leave to stand for 5 minutes.
- Place the flour, baking powder and bicarbonate of soda in a bowl and fork to mix. Whisk the eggs together in a small jug. Pour the eggs gradually into the butter mixture in the pan, whisking all the while until they are completely absorbed. Finally, whisk in the flour mixture slowly and gently until you have a smooth batter. Pour and scrape evenly into the tins.
- Bake in the oven for about 7 minutes (see Recipe Tip for instructions for normal sandwich tins), until the cakes are shrinking away at the edges and a cake tester comes out cleanish; it is a damp cake, though, so it’s fine if a few crumbs cling to the cake tester. Leave the cakes to cool in their tins until cold.
- To make the icing, sift the icing sugar into a bowl. This is one of the few jobs in the kitchen I hate, so I wouldn’t tell you to do it if it wasn’t necessary. In another large bowl (or the bowl of a freestanding mixer fitted with a whisk), beat the butter and peanut butter together very thoroughly; that’s to say, for 3 minutes if you’re using a mixer or 5 minutes with a handheld electric whisk, until it is a light, fluffy and creamy mixture. Beat in the vanilla extract and salt.
- Still beating, but now at a slightly lower speed, patiently add the sieved icing sugar a spoonful at a time until you’ve used half of it, then beat in the rest in three batches. Turn up the mixer a little and carry on beating for 2 minutes, or for 3 minutes with a handheld electric whisk. Scrape down the sides to incorporate any icing sugar clinging to the bowl and beat again for 30 seconds–1 minute. Still beating, add the cream a tablespoonful at a time and, when it’s all in, carry on beating for 4 minutes (or for 6 minutes with a handheld electric whisk) until you have a soft, aerated and moussily light mixture.
- Peel away the lining papers from the cakes and place one of the layers, flat-side up, on a cake stand or plate. Spread – armed, ideally, with a bendy spatula and a small offset spatula – the icing about 1cm thick, taking it right out to the very edges of the circle. This will bulge out a bit when you place the other layers on top, which will make it easier for you to ice the sides. Top with your second layer, and repeat until you have 4 layers with about 1cm of icing between each one. Then spread the remaining icing over the top, again about 1cm thick. Use the bendy spatula to get a dollop of icing onto the side of the cake, then spread it gently to cover and smooth, ideally with the small offset spatula. Carry on like this, with your 2 tools, until the cake is covered all the way round. Run the offset spatula on top and around the cake again to smooth the icing. Leave the cake plain or decorate with the chopped peanuts or as your heart desires.