For the sponge
Pinch of sea salt
3 large eggs
75g light muscovado sugar
For the filling
75g dark chocolate (about 70 per cent cocoa), broken into pieces
375g chestnut purée
60g light muscovado sugar
One-and-a-half teaspoons vanilla extract
180ml whipping cream
Christmas figurines to decorate
Icing sugar for dusting
A Bûche de Noël is the French equivalent of our Christmas pudding, and in typical style has glamorous all-round potential, like so much of their patisserie.
To make the sponge, heat the oven to 200C/gas mark 6. Butter a 23 x 32cm Swiss roll tin, line it with baking paper and butter this also. Sift the cocoa into a bowl and add the salt. Place the eggs and muscovado sugar in a bowl and whisk for 8-10 minutes, using an electric whisk, until the mixture is pale and mousse-like. You can also do this in a food processor, using the whisking attachment, in which case reduce the time to about 5 minutes. Lightly fold in the cocoa in two goes. Pour the mixture into the prepared tin and smooth it using a palette knife. Give the tin a couple of sharp taps on the work surface to eliminate any large air bubbles and bake the sponge for 8-10 minutes, until set and springy to the touch.
Lay out a clean tea towel and sift over a fine layer of icing sugar. Turn the cake out on to it and carefully roll it up with the tea towel, leaving the paper in place, starting at the short end so you end up with a short, fat roll. Leave to cool for 40-60 minutes.
To make the filling, gently melt the chocolate in a bowl set over a pan with a little simmering water in it, then set it aside to cool to room temperature. Cream the chestnut purée, sugar and vanilla in a food processor, then add the chocolate. Transfer the mixture to a bowl. Whip the cream until it forms soft peaks, and fold it into the chocolate chestnut mixture in two goes.
Carefully unroll the sponge and peel off the paper parchment. Spread with half the chocolate chestnut mousse, then roll the sponge up again and tip it on to a long serving plate, seam downwards. Smooth the rest of the filling over, then make lines along its length with a fork, swirling the ends to create a log effect, and making a few knots on the log too. Decorate it with Christmas figurines.
Chill the roulade for an hour. Shortly before serving shower the icing sugar.
Taken from 'Gorgeous Christmas' by Annie Bell (Kyle Cathie, £14.99).