Pretty pink raspberry mousse, exquisitely clean lines of vanilla sponge and dark chocolate ganache, finished with delicate shards of tempered chocolate and raspberries. Who needs a fancy pâtissérie when you can create such perfection in your own home?
Heat the oven to 180°C/160°C fan/350°F/Gas 4.
Make the joconde sponge. Whisk the egg whites and caster sugar in a stand mixer fitted with the whisk, on medium speed until they form stiff peaks. Meanwhile, sift the ground almonds and plain flour into a large mixing bowl.
Add the melted butter and vanilla to the almond and flour mixture and beat them together until the mixture is thick and smooth. Add one third of the egg whites and thoroughly stir in to soften and lighten the mixture. One third at a time, fold in the remaining egg whites, using a large metal spoon or plastic spatula.
Divide the mixture equally between two of the prepared baking sheets, using a palette knife to spread the batter out evenly and ensuring the sponges will be larger than 24 x 22cm. Bake for 15–20 minutes, until the sponges spring back when you press them gently in the centre. Remove the sponges from the oven and leave them to cool on the trays for 5 minutes. Then, turn out the sponges onto two fresh sheets of baking paper and remove the baking paper that’s now uppermost on the sponges. Place a clean tea towel on top of the sponges and leave them to cool completely.
Make the raspberry purée. Blitz the raspberries in a food processor and pass the pulp through a sieve into a jug to remove the pips. Discard the pips in the sieve.
Make the syrup. Measure out 20g of the raspberry purée (set aside the remainder), and put it in a small saucepan with the caster sugar and 30ml of water. Place the pan over a medium heat and heat until the sugar has dissolved. Stir in the raspberry liqueur to combine, then remove the pan from the heat. Leave the syrup to cool completely.
Meanwhile, make the raspberry mousse. Soak the gelatine leaves in a bowl of cold water for 5 minutes to soften. Blitz the raspberries in a food processor and pass them through a sieve into a jug to remove the pips. Tip the purée and caster sugar into a saucepan set over a medium heat. Bring the mixture to the boil, then drain the gelatine, squeezing out the excess water, and whisk it into the hot purée. Remove the pan from the heat and leave the mixture to cool to room temperature.
When the mixture is cool, in a bowl and using an electric hand whisk, whisk the whipping cream to soft peaks. Fold the raspberry mixture through the whipped cream. Set aside.
Prepare the chocolate ganache. Place the chocolate in a heatproof bowl. Pour the cream into a small saucepan and place it over a medium heat. Bring it to the boil, then immediately remove it from the heat and pour it over the chocolate in the bowl. Leave for 2 minutes, then stir until smooth. Stir in the butter until fully incorporated and set aside.
Using the metal frame as a guide, cut two rectangles of joconde sponge. Set the metal frame on the remaining lined baking sheet and place one rectangle of joconde sponge inside the frame to create a base. Brush the sponge with some of the raspberry syrup.
Pour the ganache onto the sponge and, using an offset spatula or a knife, spread it out evenly. Top with the second layer of joconde sponge and brush that with raspberry syrup, too. Pour the raspberry mousse on to the top layer of sponge and spread it out evenly, as before. Transfer the baking sheet to the fridge and chill the slice until firm.
Make the raspberry jelly. Soak the gelatine leaves in a bowl of cold water for 5 minutes to soften. Measure out 50g of the remaining raspberry purée and place it into a small saucepan with the caster sugar and 50ml of water. Place the pan over a medium heat and bring the liquid to the boil. Drain the gelatine leaves, squeezing out the excess water, and add them to the hot purée. Stir to melt the gelatine, then leave the mixture to cool to room temperature. Once it’s cooled, remove the slice from the fridge and pour the jelly on top of the set raspberry mousse. Return the slice to the fridge and leave the jelly to set (about 30 minutes).
Meanwhile, make the chocolate decorations. Melt 75g of the dark chocolate in a heatproof bowl set over a pan of barely simmering water and heat it up until it reaches 41°C on the cooking thermometer. Remove the bowl from the pan, then stir in the remaining 25g of chocolate, until melted and cooled to 32°C.
Place the acetate sheet or baking paper on your worktop and spread the tempered chocolate on top in an even layer about 3mm thick. Leave for about 10 minutes, until almost set, then use a sharp knife to score thin shards from the sheet of chocolate. Leave to set, then carefully peel off the shards.
Once the jelly has set, carefully remove the metal frame from the whole slice. Trim the edges to neaten and then cut the slice into 12 equal portions – clean your knife between each cut to ensure perfectly precise lines.
Decorate the top of each slice with a raspberry, pomegranate seed, chocolate shard, mint tip and piece of gold leaf (if using).