I first made this cake last year and it’s my all-time favourite chocolate cake. You just can’t beat that chocolate and hazelnut combination. The nuts keep the cake incredibly moist.
Chocolate Hazelnut Cake
For the cake
250g whole blanched hazelnuts, roasted
200g butter, cubed, plus extra for greasing
200g dark chocolate, broken into squares
6 medium eggs, separated
200g caster sugar, preferably golden
3 tbsp hazelnut liqueur or amaretto liqueur
150g chocolate and hazelnut spread (I used Nutella)
50g dark chocolate
50g unsalted butter
Preheat the oven to 180C/160C fan. Grease a 23cm springform cake tin and line the base with baking parchment.
Place 200g of the hazelnuts in a food processor and blend them until they are finely ground, the consistency of fine breadcrumbs. Do not over process the nuts as they will become greasy and you want some texture remaining. Set the remaining 50g hazelnuts aside for decorations later on.
Put the butter and chocolate in a heatproof bowl and set it above a pan of gently simmering water. Stir gently until all the chocolate has melted, then remove the bowl from the heat. Stir in the ground hazelnuts and leave the mixture to cool for 5 minutes.
Beat the egg yolks and sugar together with an electric hand-whisk for at least 5 minutes until pale and fluffy, then stir into the chocolate mixture until well combined.
In a clean bowl, whisk the egg whites until stiff peaks form but do not over whisk.
Quickly stir the hazelnut liqueur or amaretto into the chocolate mixture. Add about 2 tbsp of the whisked egg whites and stir until thoroughly incorporated, then gently fold in the remaining egg whites.
Pour the mixture into the tin and bake in the centre of the oven for 35–40 minutes or until the cake is well risen and firm.
Remove the cake from the oven and leave it to cool in the tin for 30 minutes. Turn the cake out on to a serving plate, peeling off the lining paper and leave it to cool completely.
For the topping, melt the chocolate and butter together and stir until smooth. Slightly warm the Nutella (I give it a 20 second blast in the microwave) and combine with the chocolate. Let it cool to room temperature and spread the chocolate and hazelnut mixture over the top of the cooled cake. Sprinkle with the hazelnuts that you set aside – these can be whole or chopped, whatever you prefer.
The cake keeps well in an airtight container in the fridge for about 5 days. Do let it come to room temperature before serving.