There is something irresistible about the combination of chocolate and peanut butter. Here I have filled a chocolate mocha cake with velvety smooth peanut mousse and topped the cake with a chocolate glaze and peanut brittle and then taken the whole cake to my peanut butter mad son for his birthday cake. Needless to say he was delighted and has declared this to be the best peanut butter cake ever.
The cake is very rich so best served in small slices.
Chocolate & Peanut Butter Mousse Cake
For the Cake
- 150g plain flour
- 50g cocoa powder
- ½ tsp baking powder
- ½ tsp bicarbonate of soda
- 185g caster sugar
- 1 tsp salt
- 140g buttermilk
- 100g unsalted butter, melted
- 50ml strong coffee
- 1 tsp vanilla extract
- 3 large eggs, lightly beaten
For the Mousse
- 10 egg yolks
- 200g caster sugar
- 80g butter
- 200g smooth peanut butter
For the Glaze
- 4 sheets of gelatine, soaked in cold water for 10 minutes (see Notes)
- 200g caster sugar
- 150g double cream
- 250g glucose syrup
- 50g dark chocolate (min 70% cocoa)
- 50g cocoa powder, sifted
For the Peanut Brittle
- Sunflower oil, for greasing
- 75g soft light brown sugar
- 200g caster sugar
- 75g golden syrup
- 25g unsalted butter
- ½tsp bicarbonate of soda
- Pinch of salt
- 175g skinned peanuts
- To make the cake, preheat the oven to 180C/160C fan. Grease a 20cm springform tin and line the base with baking parchment.
- Sift the flour, cocoa powder, baking powder and bicarb and into the bowl of your stand mixer or a large bowl and add the sugar and salt.
- Pour in the buttermilk, melted butter, coffee, vanilla essence and beaten eggs. Lightly beat together until just combined. (Do not overbeat or the cake will be dense and heavy).
- Pour into the prepared tin and bake in the preheated oven for 20 – 25 minutes until firm to the touch and a skewer inserted into the center comes out clean.
- Leave the cake to cool in the tin for 5 minutes before turning out onto a cooling rack to cool completely.
- Once cooled, cut the cake into two horizontally.
- While the cake is cooling, make the peanut mousse. Place the egg yolks into the bowl of your stand mixer and beat on high for 2 minutes.
- Meanwhile place the sugar and 120ml of water into a small saucepan. On a low to medium low heat stir the mixture until the sugar has completely melted. Bring the mixture to a boil and, using a sugar thermometer, bring the mixture to 120C (soft-ball stage).
- With the beater running on full speed, slowly pour the hot sugar syrup onto the egg yolks. Continue beating the mixture on full speed for another 10 minutes until the mixture looks pale and has tripled in volume, and then pour the mixture into a large bowl.
- Now put the butter and peanut butter into the bowl of your stand mixer and beat for 1 minute until smooth and combined.
- Take a heaped serving spoon full of the egg mixture and beat it into the peanut mixture to loosen.
- Gently but swiftly fold the remaining egg mixture into the peanut mixture, keeping as much air in as possible to keep the mousse light.
- Place the bottom slice of cake onto a serving platter and enclose in a tight fitting cake ring.
- Top with the peanut butter mousse and place the cake in the fridge for 30 minutes.
- Top with the second layer of cake and return to the fridge for another 30 minutes.
- Meanwhile, make the glaze. Place the sugar, cream and 40ml of water into a small saucepan and heat until boiling. Remove the pan from the heat and stir in the glucose.
- Add the cocoa powder and the dark chocolate and stir to combine.
- Add the squeezed out gelatine and stir until dissolved, then strain through a colander into a jug.
- Pour the glaze over the cake and leave to set in the fridge for another hour.
- While the glaze is chilling make the brittle. Grease a baking sheet with sunflower oil. Put both sugars and the golden syrup into a medium-sized saucepan. Add 75ml water and stir over a medium heat until the sugar has completely dissolved. Add the butter and stir until melted.
- Bring the mixture to the boil and continue to cook until the temperature reaches 154°C on a sugar thermometer.
- Remove the pan from the heat and immediately add the bicarbonate of soda, salt and nuts, stirring well as the mixture foams up.
- Pour on to the baking sheet and spread level with the back of a wooden spoon. Once the brittle is completely cold and hardened, break it into pieces and sprinkle over the cake to decorate.
- You can store any left over brittle in small freezer bags.
Notes: I use Dr. Oetker Platinum Strength gelatine leaves. If you are using a different brand, please refer to the manufactures instructions.