Grease a 20cm / 8 in loose-bottomed cake pan and line the base with baking paper. Line the sides
with strips of foil. Slice the Madeira cake and use it to line the bottom of the cake tin, cutting
the pieces to fit. Mix the brandy with the coffee and drizzle this over the base.
Melt the two types of chocolate in separate heatproof bowls set over pans of hot water. Whip the
cream until it holds its shape, then divide it between two bowls. Stir the plain chocolate into one
of the bowls and the white chocolate into the other.
Spoon alternating blobs of white and plain chocolate mixture into the cake pan and swirl them
into one another with a skewer. Smooth over the top and then chill for at least 2 hours.
Carefully remove the mousse from the cake pan and peel off the foil. Place the mousse on a
serving plate and chill again until ready to serve.