This rich seasonal treat provides the perfect alternative to the traditional iced fruit cake
1. Preheat the oven to 190 decrees. Grease line and flour a Swiss roll tin (jelly roll pan).
2. Whisk the egg yolks with all but 25g of the sugar until pale and thick. Add the vanilla extract.
3. Whisk the egg whites with the cream of tartar until they form soft peaks, add the reserved caster sugar and continue whisking until the mixture is stiff and glossy.
4. Fold half the flour into the yolk mixture. Add a quarter of the egg whites and fold in to lighten the mixture, fold in the remaining flour then the remaining egg whites.
5. Spread the mixture in the tin. Bake for 15 minutes. Turn on to paper sprinkled with caster sugar. Roll up and leave to cool.
6. Put the cream into a small pan and bring it to the boil. Put the chocolate in a bowl and add the cream. Stir until the chocolate has melted, then beat until it is fluffy and has thickened to a spreading consistency. Mix one-third of the chocolate cream with the rum or Cognac.
7. Unroll the cake and spread with the rum mixture. Re-roll and cut off about a quarter at an angle. Arrange to from a branch. Spread the chocolate cream over the cake. Mark lines all down the roll with a fork, add Xmas decorations and dust with a little icing sugar.