Heat oven to 190C/fan 170C/gas 5. Butter
and line the base and sides of a 30 x 35cm
Swiss roll tin with baking parchment.
Separate the eggs, putting them into two
large mixing bowls. Add the sugar and 2 tbsp
water to the egg yolks. Using an electric whisk
or tabletop mixer, whisk the sugar and yolks
for about 5 mins until the mixture is light in
colour and thick enough to leave a trail when
the whisk blades are lifted. Sift in the flour
and cocoa, then fold in lightly, using the
whisk blades or a large metal spoon.
Using a clean whisk, beat the egg whites
until they are stiff, then fold into the cake
mixture in three batches, again using the
blades to preserve as much air as possible.
Pour the mixture evenly over the prepared
tin, then carefully spread to the edges. Bake
for 10-12 mins, or until the cake feels firm
to the touch. Put a large sheet of baking
parchment on the work surface and sprinkle
lightly with caster sugar. Turn the cake out
onto the parchment and peel off the lining
paper. Cover with a clean tea towel, then
leave to cool completely. Trim a little cake
from all the edges, then score along the edge
of one of the long sides of the cake and roll
up from there, using the paper to help you,
rolling the paper inside the cake.
To make the icing and filling, bring the
cream to the boil in a small pan, remove
from the heat, then break in 400g of the
chocolate. Stir until it is melted and smooth.
Leave to cool, then chill until it is spreadable,
about 1 hr. Chop the remaining chocolate,
spoon a third of the icing into a bowl, then
stir them together to make the filling.
Carefully unroll the cake, then spread all
the filling over to within 2cm of the edges.
Roll up the cake again using the paper to
help you, then set on a board.
Cut a thick diagonal slice off one end of
the cake. Transfer the larger piece of cake to
a board or flat serving plate. Spread a little
icing over cut side of the small piece of cake
and fix it to the large roll to make a stump (as photo). Spread remaining icing over the
cake, then dust with icing sugar to serve.