1 store-bought double unfilled 20cm round chocolate sponge cake or Gluten-free Chocolate Sponge, reserving 1 cake for another use
1/2 cup raisins, chopped
1/2 cup dark rum
3/4 cup caster sugar
3/4 tsp powdered gelatine
1 Tbsp water
1 egg yolk
Extra . cup water
220g dark chocolate, melted, cooled
200ml thickened cream, whipped to soft peaks
Extra 100g dark chocolate, finely chopped
Extra 100ml thickened cream
Muscatels, to garnish
Chocolate curls, to garnish
Note: Allow 30 minutes chilling time
Line a 22cm cake tin with baking paper. Slice cake into 3 thin discs, reserving 1 for another use. Combine raisin, rum and 1/4 of the sugar in a small saucepan and simmer over a low heat for 4 minutes. Set aside to cool.
Mix gelatine and water in a small microwave bowl and set aside for 3 minutes to bloom. Drain raisin, reserving liquid, then add 1/4 cup of the liquid to gelatine. Microwave in 10-second bursts until gelatine dissolves.
Put egg and yolk in the bowl of an electric mixer and beat on high, using whisk attachment, until light. Put extra water and remaining sugar in a small saucepan and cook over a high heat until syrup reaches 119C on a cook’s thermometer. With motor running, add syrup and gelatine mixture. Beat until cool.
Fold melted chocolate into egg mixture, then fold in whipped cream. Put 1 cake disc in prepared tin and drizzle with a little of the reserved raisin liquid. Top with raisin. Spoon over 2/3 of the chocolate mousse, then top with second cake disc. Drizzle with remaining raisin liquid, then spoon remaining mousse on top. Smooth with a palette knife and refrigerate for 30 minutes or until firm.
Put extra chocolate in a large heatproof bowl. Put extra cream in a small saucepan over a medium heat and bring to the boil, then pour over chocolate and whisk until smooth. Turn out cake onto a serving plate and pour over chocolate icing. Allow icing to set slightly, then decorate cake with muscatels and chocolate curls to serve.