Coffee, dark chocolate and hazelnut meringue layer cake

Preheat the oven to 180°C. Grease and line the sides of 2 x 18cm springform cake tins.

To make the cake, sift the flour, baking powder, bicarbonate of soda and salt in a bowl and set aside.

Place the butter, chocolate and sour cream in the bowl of a double boiler over a pan of simmering water and stir until smooth.

Whisk the eggs and sugar together by hand in a large bowl until smooth. Pour the chocolate mixture into the egg mixture and whisk gently. Add the coffee and mix. Fold the flour mixture into the chocolate mixture with a spatula. If it becomes lumpy whisk again briefly.

Pour the mixture into the baking tins and bake until a skewer inserted in the centre comes out clean, about 30 minutes. Allow the cake to cool before turning out.

For the meringue, place the hazelnuts on a baking tray and bake until a nice brown colour is achieved, about 10 minutes. Remove and allow to cool.

Turn the oven down to 130°C. Set aside 100g of the hazelnuts for later use.

Place the remaining hazelnuts, 60ml (¼ cup) of the sugar and flour in a food processor and process until fine.

Line a baking tray with baking paper and place 2 x 18cm buttered cake rings without bases on the paper – this is just to provide a mould for the meringue.

Place the egg whites and cream of tartar in a stand mixer with the whisk attachment and beat on high until stiff peaks are formed, about 4 minutes. Gradually beat in the remaining sugar and continue to beat for a minute longer after the sugar has been added.

Gently fold the nut mixture into the egg whites. Place half the mixture in each cake ring and smooth with an offset spatula. Bake until the meringue is crisp and light brown, about 90 minutes. Remove and allow to cool completely. Gently remove the cake rings with a sharp knife and peel the baking paper off the meringues. Set aside.

For the coffee syrup, place the sugar and water in a saucepan over medium heat and stir until the sugar has dissolved. Add the coffee and set aside.

To make the buttercream, place the sugar and water in a saucepan over medium heat with a candy thermometer if you have one, otherwise use a bowl of water alongside to check the stage.

Place the egg yolks in a stand mixer fitted with the whisk attachment and beat on high until pale and the yolks have increased in volume. The eggs should be done when the sugar reaches the softball stage. Watch the sugar mixture closely while the eggs are beating. Brush the sides down with a pastry brush every few minutes to prevent crystallisation on the sides of the pan. The sugar mixture must reach the softball stage of 110°C. Keep beating the eggs and pour the sugar mixture into the egg mixture without it touching the sides of the bowl. Keep beating until it reaches room temperature.

Reduce the speed to medium and add the butter a little at a time, beating after each addition, about 10 minutes. Continue beating while slowly adding the espresso.

For the ganache, put the chocolate into a heatproof bowl. Heat the cream in a saucepan over medium heat until simmering then pour over the chocolate and let it stand for about 10 minutes. Stir to ensure all the chocolate has melted. Whisk with a hand beater until thick and creamy. Allow to stand for a while until it thickens and becomes the same consistency as the buttercream.

Place one cake on a serving plate and drizzle with half the syrup. Cover with a layer of coffee buttercream and sprinkle with some of the reserved hazelnuts, chopped. Top with a layer of the meringue and more buttercream. Repeat layers, pour the ganache over the top and decorate with a few whole hazelnuts and chocolate decorations, as desired.