- 3 free-range egg whites
- 150g/5oz icing sugar
- 3 free-range eggs
- 150g/5oz ground hazelnuts
- 50g/1¾oz plain flour
- 25g/1oz unsalted butter, melted, plus extra for greasing
- 4 free-range eggs
- 110g/4oz caster sugar
- 75g/3oz plain flour
- 25g/1oz cocoa powder, sifted
- 25g/1oz butter, melted
- 1 litre/1¾ pint double cream
- 9 tbsp hazelnut paste
- 50ml/1¾fl oz cognac
- 250g/9oz caster sugar
- 5 free-range egg whites
- 1 lemon, juice only
- 110g/4oz butter, softened
- 50ml/1¾fl oz cold strong coffee
- 3-5 small meringue shells
- 9-15 small marshmallows
- 2 tbsp cocoa powder, to sieve
- For the sponge cakes, preheat the oven to 180C/350F/Gas 4 and lightly grease and line the base of two 25cm/10in loose bottomed cake tins.
- For the hazelnut sponge, in a clean bowl, whisk the egg whites and 50g/1¾oz of the icing sugar until stiff peaks form when the whisk is removed.
- In a separate bowl, whisk together the remaining icing sugar and whole eggs until thickened and pale in colour.
- Fold in the ground hazelnuts gently, sift in the flour and mix in the melted butter.
- Finally, gently fold in the whisked egg whites until incorporated.
- Spoon the mixture into one of the prepared cake tins, then tap to remove any air pockets.
- Place in the oven for 16 minutes, or until risen and just firm to the touch.
- Remove from the oven and cool briefly before tipping out onto a rack to cool completely.
- For the chocolate sponge, place the eggs and sugar in a bowl and whisk for 4-5 minutes, or until thickened and very pale.
- Sift in the flour and cocoa powder and add the melted butter. Gently fold the batter to combine.
- Spoon the mixture into the remaining cake tin, then tap to remove any air pockets.
- Bake in the oven for 16 minutes, or until risen and just firm to the touch – do not overcook this sponge, as it will become dry.
- Remove from the oven and cool briefly before tipping out onto a rack to cool completely.
- For the hazelnut cream, in a bowl combine the cream and hazelnut paste. Whisk until soft peaks form when the whisk is removed. Place in the fridge until ready to use.
- For the coffee flavoured meringue buttercream, place the sugar and 125ml/4½fl oz water in a pan and slowly bring to the boil. Continue to heat until the syrup reaches 110C/230F on a sugar thermometer.
- Meanwhile, place the egg whites in the bowl of a food mixer (make sure it’s scrupulously clean) and add a squeeze of lemon juice. Whisk until firm peaks form.
- Keep checking the temperature of the syrup and as soon as it reaches 121C/250F, remove the pan from the heat and immediately resume whisking the egg whites.
- With the beater at its lowest speed, pour in the sugar syrup, in a slow steady stream, making sure it is clear of the whisk (the syrup is extremely hot and could splash out of the bowl if it hits the whisk).
- Continue beating for about five minutes, until the meringue is tepid.
- Add the butter and continue to beat until it is all incorporated. Beat in the cold coffee and set aside to cool completely.
- To assemble the gateâu, horizontally cut each sponge cake into three layers to form six thin slices.
- Place one sponge layer on a serving plate and drizzle over a spoonful of cognac. Spread over a thin layer of hazelnut cream.
- Top with another layer of sponge, cognac and cream and repeat with the remaining sponges until you have a stack of six sponges filled with five layers of cream.
- To decorate, using a pallet knife spread the coffee flavoured meringue buttercream around the sides of the cake and over the top, finishing with a swirl pattern.
- Use a little buttercream to stick the marshmallows to the meringue shells. Dust with cocoa powder, then place on the top of the cake in a little cluster.
- Slice and serve.