Break up the chocolate into a heat proof bowl.
Pour in the double cream.
Put the bowl over a pan of barely simmering water and leave, until the chocolate has melted.
Take the bowl off the heat and with an electric hand mixer, whisk the mixture, until you have a cold creamy mixture.
Pour the brandy into a shallow dish.
Dip the biscuits, one at a time, first into the liquor, then into the chocolate cream and arrange a layer of biscuits in the base of the pudding basin.
Spread a layer of the chocolate mixture over the first layer of biscuits.
Repeat the whole process, until you have 4 layers.
Place a saucer (one that fits inside the rim of the pudding basin) on top of the mixture, put some weight on top and leave in the fridge over night.
Before serving, dip the basin in hot water for a few seconds and turn the pudding out on to a flat serving plate.
Put the cake back into the fridge for 15 mins to allow the outside to get firm again.
Finally, dust with cocoa powder.