This recipe is from A Year in My Kitchen
| 6 large eggs, separated|
| 5 oz (150g) caster sugar|
| 2 oz (50g) cocoa powder|
| Icing sugar |
|For the chocolate mousse:|
| 3½ oz (100g) dark chocolate (73% cocoa solids), broken into pieces|
| 2 small eggs, separated|
| 1 oz (25g) golden caster sugar |
|For the prune filling:|
| 8 oz (225g) no-soak prunes|
| 4 fl oz (100ml) Armagnac|
| ¼ pint (150ml) crème fraiche|
|You will also need a Deliaonline Silverwood Swiss Roll tin 8 by 12 inches (20 x 30cm), greased and lined with a single sheet of baking parchment or liner, so that it comes up 2.5cm above the edge of the tin.|
Start off by soaking the prunes in the Armagnac, preferably overnight but at least for 2-3 hours. Place them in a bowl, pour in the Armagnac and press the prunes down well into the liquor. Cover the bowl and leave till needed.Now make the chocolate mousse.
Place the broken-up chocolate and 4 fl oz (120ml) warm water in a large heatproof bowl, which should be sitting over a saucepan of barely simmering water (make sure the bottom of the bowl doesn’t touch the water.
Then, keeping the heat really low, melt the chocolate slowly.
Now take it off the heat and stir it briskly till it’s smooth, then let it cool for a few minutes. After that stir in the egg yolks and mix well with a wooden spoon.
Whisk the egg whites to the soft peak stage, then whisk in the sugar – about one-third at a time, then whisk again until the whites are glossy.
Next use a metal spoon to fold first one spoonful of the egg whites into the chocolate mixture to loosen it, then carefully fold in the rest.
Place the bowl, covered with clingfilm, in the fridge for at least an hour.
Now pre-heat the oven to gas mark 4, 350F, 180C.
Now you can get on with the cake: place the egg yolks in a bowl and whisk until they start to thicken, then add the caster sugar and continue to whisk until the mixture thickens slightly, and finally mix in the cocoa powder.
In another bowl beat the egg whites up to the soft peak stage, then carefully cut and fold the egg whites into the chocolate mixture. Now pour the whole lot into the prepared tin and cook in the centre of the oven for 20-25 minutes until springy and puffy.
Leave the cake to cool in the tin (it will shrink a bit, but that’s normal), then when it’s cold turn it out onto an oblong of greaseproof paper that has been generously dusted with icing sugar.
Peel off the lining paper from the bottom of the cake (which will now be facing upwards), then spread the chocolate mousse over the cake, using a palette knife.
Place the soaked prunes and the crème fraiche in a mini-chopper or food processor and give them a whiz – not too much, you need to keep the texture of the prunes.
Now spread this mixture on top of the mousse. Finally roll up the cake to a log shape, using the greaseproof paper to help you – if it cracks a little, that only adds to the authenticity!
Store, covered, in the fridge.