Chocolate comes from cocoa beans, which first grew on trees in Central America. Raw cocoa beans are really good for you, full of vitamin C and magnesium, but they’re bitter. They actually also have a fair amount of caffeine in them. By around 2000BC people in Central America (modern Mexico) were grinding up the beans and making them into a hot or cold spicy chocolate drink with vanilla or chilli pepper. During the 1400s AD, the Aztec Empire controlled most of Central America. The Aztec government made people pay a lot of their taxes in cocoa beans, because they were expensive and you could store them for a long time. Once the government made people use cocoa beans as money, most people couldn’t afford to actually eat them anymore, and only rich people drank the chocolate drinks. Would you believe some enterprising Aztecs actually made counterfeit cocoa beans.
This cake is pure chocolate indulgence. A decadent, versatile layer cake that will delight any chocaholic. I have served this for afternoon tea, made it for a birthday and served it for dessert. You could omit the chocolate collar but I think it finishes it off beautifully and makes it look more special.
Hazelnut Brownie & Chocolate Mousse Cake
For the Brownie Base
- 50g dark chocolate (70% cocoa)
- 75g unsalted butter
- 85g caster sugar
- 1 egg
- 40g plain flour
- 70g roasted chopped hazelnuts
For the Chocolate Sponge
- 40g ground almonds
- 40g icing sugar
- 2 eggs, separated
- 20g caster sugar
- 25g plain flour, sifted
- 10g cocoa powder, sifted
- 12g butter, melted
For the Crispy Layer
- 50g chocolate (70% cocoa)
- 50g milk chocolate
- 50ml double cream
- 40g rice crispies
For the Chocolate Mousse
- 200g dark chocolate (70% cocoa)
- 6 egg yolks
- 60g caster sugar
- 1 ½ gelatine leaves (see notes)
- 400ml double cream
For the Chocolate Collar and Decorations (optional)
- 250g dark chocolate (70% cocoa)
- To make the Brownie Base preheat the oven to 190C/170C fan. Grease and line a 20cm sandwich tin with, baking parchment.
- Melt the chocolate and butter in a heatproof bowl over a saucepan of simmering water, making sure that the bowl does not touch the water. Stir until smooth and remove the bowl from the heat.
- In a separate bowl beat together the sugar and eggs until combined and stir into the warm chocolate mixture.
- Sift over the flour, add the nuts and stir until combined. Divide the mixture between the prepared tins and bake in the preheated oven for 12-15 minutes
- Turn the cakes out onto a cooling rack and remove the parchment paper.
- To make the Chocolate Sponge, grease and base line with parchment paper a 20cm sandwich tin. Turn the oven down to 180C/160C fan.
- In a bowl, beat the egg yolks with the icing sugar until pale and creamy then beat in the almonds.
- In a separate bowl beat the egg whites with the sugar until stiff.
- Fold two thirds of the egg whites into the egg yolk mixture.
- Add the remaining third of the egg whites and sift over the flour, cocoa powder and baking powder. Gently fold everything together until incorporated.
- Stir one tablespoon of the batter into the warm melted butter then fold the butter mixture into the cake batter. Pour the mixture into the prepared cake tin and bake for 10 – 12 minutes.
- Turn the cake out onto a cooling rack lined with baking parchment sprinkled with sugar.
- For the Crispy Layer lightly grease the sides of a 20cm sandwich tin and base line with baking parchment.
- Break the chocolate into a bowl over simmering water, making sure the bowl does not touch the water, and leave the chocolate to melt.
- Add the cream and rice crispies and stir until well combined. Spoon the mixture into the prepared tin and refrigerate until set.
- For the Chocolate Mousse melt the chocolate in a bowl over simmering water, making sure the bowl does not touch the water. The chocolate should be about 50C on a sugar thermometer.
- Place the egg yolks with the sugar into a heatproof bowl suspended over simmering water without the bowl touching the water.
- Stir constantly until the mixture feels hot. Remove the bowl from the heat and stir in the squeezed out gelatine. Stir until dissolved.
- Beat the mixture with an electric whisk until pale, thick and creamy.
- Whisk the cream until thick and creamy and then fold a third of the cream into the warm chocolate.
- Fold in the egg yolk mixture followed by the remaining cream.
- To complete the cake place the brownie base onto a serving plate and tightly enclose with a spring from ring.
- Pour over a third of the chocolate mousse and spread out evenly.
- Remove the crispy layer from the fridge and place over the mousse. Spread with another third of the chocolate mousse.
- Place the chocolate sponge over the mousse and spread with the remaining chocolate mousse.
- Refrigerate for at least 4 hours until set.
- To make the chocolate collar and decorations place 200g of the chocolate into a microwave bowl and heat in 30 second bursts until just warm and melted.
- Chop or grate the remaining chocolate finely and add to the melted chocolate. Stir gently without beating in any air (too much air will make the chocolate cloudy) until all the chocolate has melted. If that proves impossible give it another 10 second burst in the microwave.
- Measure and cut a strip of baking parchment the height of the cake and 4 cm longer than the circumference of the cake.
- Place on a slightly larger sheet of baking parchment to avoid messing up your worktop with chocolate.
- Spread the chocolate evenly over the parchment strip leaving 2cm free either end.
- To make the chocolate waves cut 3 smaller strips and spread with chocolate and drape over a wooden spoon. When they are beginning to set, pop them in the fridge to set completely.
- Remove the cake from the fridge and take off the spring form clip. You can heat the ring a little with a cook’s blowtorch to make this easier.
- Watch the chocolate collar carefully. When it just about begins to set, it must be flexible but firm enough to stay on the parchment paper. Lift the chocolate covered parchment and carefully press around the cake setting the bottom edge down against the serving plate.
- Gently peel away the paper from the outside, just enough to stick the other end down against it. Place the cake back in the fridge for another 30 minutes to set the chocolate completely.
- Remove from the fridge and carefully peel away the parchment paper. Carefully peel the parchment paper off the chocolate waves and use to decorate the top of the cake.
Notes: I have used DrOetker Diamond gelatine leaves but if you are using a different brand please refer to the manufacturer’s instructions.