Hazelnut sponge with cocoa
Whisk the egg whites together with sugar until stiff peaks form when you lift the whisk from the mixture.
Preheat the oven to 180°C.
Gently fold the hazelnuts, flour, and cocoa powder into the stiff egg white mixture.
Spread the mixture evenly on a baking sheet lined with parchment paper, about 1 cm thick.
Bake at 180°C for 15 minutes.
Cocoa sponge
Whisk the eggs together with sugar.
Preheat the oven to 180°C.
Gently fold the flour and cocoa powder into the egg mixture.
Spread the mixture evenly on a baking sheet lined with parchment paper, about 1 cm thick.
Bake at 180°C for 15 minutes.
Leave to cool completely before cutting out into 3 cm discs.
Chocolate cream
Soak the gelatine in plenty of cold water and let it swell.
Heat the milk, cream, egg yolk, and sugar to 80°C, then remove from heat and add the gelatine.
Stir well to combine, and then pour the mixture over the hazelnut paste and chocolate.
Let the chocolate melt and mix until smooth.
Refrigerate until well chilled.
Whip until you get a stiff cream for piping.
Hazelnut cream
Soak the gelatine in plenty of cold water and let it swell.
Gently heat the hazelnut paste and chocolate to 45°C until melted.
Dissolve the gelatine in a little of the cream. Whip the remaining cream.
Combine all the ingredients together, stirring quickly to prevent the gelatine from cooling and curdling the chocolate and hazelnut mixture. Use the hazelnut cream immediately.
Chocolate glaze
Heat together the cream, butter, glucose, and water and bring to a boil.
Pour over the chocolate to melt, and mix to form a smooth glaze, taking care not to incorporate any air bubbles.
Gently fold the hazelnuts into the glaze. The glaze should be warmed to around 45°C when used to cover the cakes.
Assembling the cake
Pipe a little chocolate cream onto each of the cocoa sponge circles, sprinkle with crushed hazelnuts, and freeze.
Pipe hazelnut cream into the silicone moulds to fill them halfway.
Turn out the frozen cocoa sponges and place an inverted cocoa sponge into each mould.
Top with hazelnut cream and hazelnuts. Fill the moulds with more hazelnut cream, top with a hazelnut sponge and refrigerate until well chilled.
Once chilled, cover with the chocolate glaze and decorate as desired.
