Helen Goh's Rigo Jancsi cake (flourless chocolate mousse cake)

Helen Goh's simplified take on the Hungarian chocolate cake.
Helen Goh's simplified take on the Hungarian chocolate cake. Photo: William Meppem
Dietary
Gluten-free

Rigo Jancsi was a famous, Hungarian gypsy violinist who so captured the fancy of a Belgian countess – American socialite Clara Ward – when she saw him play at a Parisian restaurant in 1896 that she left her husband, Prince Joseph, for him. In short order, an elaborate chocolate cake, celebrating their scandalous love story, was conceived. Here, just in time for Valentine's Day, is my simpler, flourless version.

Ingredients

180g dark chocolate, chopped

150g unsalted butter, cut roughly into 6 pieces

1 tbsp rum

2 tbsp strong black coffee, cooled

1 tsp vanilla essence

3 eggs, at room temperature, separated

pinch of salt

60g caster sugar

100ml whipping cream

For the chocolate shards (optional)

100g dark (about 70 per cent) chocolate, chopped

For the cream layer

100ml whipping cream

½ tsp vanilla essence

¼ tsp finely ground espresso coffee

¼ tsp cinnamon powder

pinch of salt

1 tbsp icing sugar

Method

1. Preheat oven to 160C fan-forced (180C conventional). Grease and line the base and sides of a 15-16cm cake tin (with a removable base) with baking paper.

2. Combine the chocolate and butter in a medium heatproof bowl, then place it on top of a saucepan with gently simmering water. Stir gently until melted, then remove from heat and stir in the rum, coffee and vanilla. Set aside to cool for about 10 minutes, then add the egg yolks. Whisk for a few seconds to just incorporate, then set aside.

3. Place the egg whites and salt in the bowl of a cake mixer fitted with the whisk attachment and beat on medium-high speed until frothy (about 1 minute). Gradually add the sugar, one tablespoon at a time, and continue to whisk until firm peaks form.

4. Fold one third of the beaten egg whites into the chocolate mixture, then once incorporated, add the remaining egg whites and fold together until blended.

5. Spoon about a third of this mixture into the prepared cake tin and spread to form an even layer. (Cover the remaining mixture and leave in the fridge for now.) Place the cake tin into the preheated oven and bake until the cake is set (about 15 minutes). Remove from oven and cool to room temperature, then place in fridge. 

6. For the mousse layer, whip the cream either in the cake mixer or with a handheld beater until soft peaks form, then fold the cream into the left-over refrigerated chocolate mixture. Layer the mousse on top of the cooled cake base and level with a spatula. Cover and refrigerate for at least 6 hours or overnight.

7. Meanwhile, for the chocolate shards, melt the chocolate by placing in a small heatproof bowl set over a small saucepan which is half filled with water and place over low heat. Cut 2 sheets of non-stick baking paper, about 40cm long. Pour the melted chocolate down the centre along the length of the baking paper, leaving a 3cm border at the ends, then place the second sheet of baking paper on top. Press firmly with your hands to spread the chocolate into a long, thin layer, then, starting with one of the short ends, roll up the baking paper tightly into a cylinder. Place in the fridge until it sets (about 1 hour).

8. On the day of serving, place all the ingredients for the cream layer in the bowl of a cake mixer fitted with the whisk attachment and beat over medium speed until soft waves form. Spread the cream over the mousse layer and level the top with a spatula. Keep refrigerated until ready to serve.

9. When ready to serve, remove the ring from the cake tin and transfer the cake onto a serving plate. Unroll the cold chocolate cylinder in one swift movement so that it breaks into long shards. Gently press into the sides of the cake, with the curved sides sticking to the mousse – and serve.