The recipe here is an adaptation of Fanny Cradock’s 1968 recipe for ‘Never split Swiss roll’, used as the basis for the chef’s own bûche de Noël. A freestanding mixer or electric hand whisk is essential. For a chocolate sponge, replace 1 rounded tbsp of the flour with 1 heaped tbsp of cocoa powder. The icing and filling should ideally be made prior to the cake and, if you prefer, you can swap out the buttercream filling for a tart-flavoured jam (such as blackcurrant or apricot), sweetened chestnut puree or simply whipped cream. If so, you’ll need to make only half the quantity of icing to cover the cake.
SERVES: 8-10
TAKES: 1 HR
INGREDIENTS
150g dark chocolate (minimum 70%), broken into chunks
180g unsalted butter, softened
75ml sour cream
400g icing sugar, sifted
3 tbsp brandy, rum, orange liqueur or milk
1 tsp vanilla extract
100g golden caster sugar
3 medium eggs
70g self-raising flour, sifted
1 tsp vanilla extract
15g finely ground pistachios(optional) icing sugar, for dusting (optional) butter, softened, for greasing
METHOD
1 Start with the buttercream icing. Place the chocolate in a microwaveable bowl and microwave on high for 30 seconds, then stir. Return to the microwave for 10-15 seconds, then stir again. Repeat, stirring after each stint in the microwave, until the chocolate has melted. Alternatively, place the chocolate in a bowl over a pan of barely simmering water (ensuring the bottom of the bowl doesn’t touch the water) and stir occasionally until the chocolate has melted. Allow to cool to body temperature.
2 Beat the butter until smooth, then beat in the sour cream. Gradually beat in the icing sugar until all of it has been incorporated. Add the cooled melted chocolate, then the brandy (or other spirit or milk) and vanilla extract and stir until smooth. Keep the buttercream at room temperature (it will become too firm if put in the fridge).
3 To make the cake, heat oven to 200C, fan 180C, gas 6 and butter the base and sides of a 33cm x 23cm x 2cm Swiss or jelly roll tin. Line the base with baking paper and butter this, too. Place a piece of baking paper slightly larger than the tin on a wire rack, then lightly dust with flour to prevent the cake from sticking. Have all your ingredients measured out and your buttercream icing (or alternative filling, if preferred) to hand.
4 Line a small baking tray with foil. Spread the sugar on the foil-lined tray, then place in the oven for 6 mins.
5 Break the eggs into a large bowl (or use the bowl of a freestanding mixer). As soon as th
