Making the sponges: Heat oven to 180C/160C fan/gas 4. You’ll
need to make 3 rectangular chocolate
sponges, a pair of round chocolate sponges,
and 3 rectangular orange sponges to
assemble this cake, so get everything
organised first. Take a look at our Guide and the additional tips, in the Tip box below.
For every rectangular sponge, you’ll
need to line the base of a 21 x 31cm tin (see Guide in the Tips below and Related guides box, right) neatly with
baking parchment and grease the sides
with a little flavourless oil.
Start with the chocolate sponges. Put
the butter in a small saucepan and heat
gently until melted. Whisk together the
egg yolks, milk and vanilla extract in a
small bowl. Stir the flour and cocoa into the melted butter to make a paste.
Transfer this butter-flour mixture to a big
mixing bowl and whisk in the egg mixture
a little at a time – this takes elbow grease
to get it smooth, but keep going!
Put the egg whites in a bowl and beat
with an electric whisk until stiff. Add the
sugar and continue beating until the
mixture is glossy and thick. Whisk a
third of the meringue mixture into the
chocolate mixture to loosen, then use
a big metal spoon to gently fold the
remaining meringue into the batter until
just incorporated. Spread the batter
evenly in the tin. Bake for 12 mins.
Turn the cake out of the tin onto baking
parchment very lightly dusted with icing
sugar. Peel off the cake lining parchment
and cover with a clean tea towel.
Repeat steps 2 to 5 twice more. When
the third rectangular sponge is baked,
turn out as before but very loosely roll up
the sponge like a Swiss roll, starting from
one of the shortest sides, rolling up the
tea towel inside.
Make a final, fourth batch of the
chocolate sponge recipe, but this time
divide it between 2 x 20cm round,
shallow sandwich tins. Bake for 10 mins,
then turn out as instructed in step 5.
Now make the orange sponges. Follow
steps 3 to 6 again, but instead of milk,
measure 75ml of the juice from the
orange you’ve zested. If you don’t have
enough, make up the difference with
milk. Whisk in the zest.
Cool all the sponges.
Making the frosting and icing: For the orange frosting, beat together
the butter, icing sugar, orange zest and
juice. Beat until just combined – the
acidity of the orange may start to split
the mixture if overbeaten. If it looks a
little split though, don’t worry – just stop
mixing, it’ll still taste lovely. Can be kept
in the fridge for up to 3 days, but will
need bringing back to room temp to use.
When you are about to start
assembling, put all the chocolate icing
ingredients in a heatproof bowl over a
pan of barely simmering water. Gently
melt together, stirring occasionally,
until smooth and shiny.
Assembling the cake: Cut each rectangular sponge into 2 long
strips 7cm wide – trimming the long
edges off will give you a neater finish (see step A in the Guide).
It’s important to be really accurate, so
use a ruler. Trim the short edges to
neaten. When you prepare the rolled-up
sponges, just gently unroll first – don’t
worry if they crack a bit.
Spread a thin layer of orange frosting
over every strip, right to the edges. Gently
peel the strips away from their paper
– they will have stuck a bit. Start with
1 chocolate and 1 orange strip that was
rolled up to cool, and lay one on top of
the other – but don’t line up the ends.
Sit the second sponge about an inch
down from one of the ends of the bottom
sponge (it doesn’t matter which is
chocolate and which is orange). Start
to roll up from this end – the bottom
sponge should roll up and over neatly
on top of the second, so the middle of
the roll is nice and tight (see step A in the Guide).
Keep adding extra sponges and rolling
up to make a giant Swiss roll but as you
roll, the ends of each different-coloured
layer won’t finish together (and this
difference increases as the roll gets
bigger). So you’ll need to add chocolate
and orange sponges individually from
now on, rather than sandwiching
together first, then adding to the rolled cake. Where each strip ends, you’ll stick
on a matching sponge – so a chocolate
strip always continues with another
chocolate, and the same with orange
(see steps C & D in the Guide). This is the fiddly bit, as
you’ll find you’ll need to partly stick
on 1 coloured strip, then snuggle in the
other coloured strip partway through.
(This sounds more complicated than it is.
When you start to do
it, this will all make sense.) If you have a
spare pair of hands in the house, this is
the time to use them.
It’s up to you whether you find it easier
to work as a roll (see step E in the Guide), or to turn the roll
on one of its flat ends to work with (see step F in the Guide).
I started rolling, and just as it got towards
the ends and was getting quite heavy and
bulky, I flipped it to continue. Have the
round sponges to hand as you near the
end, to check whether you’ve reached
a roll of 20cm diameter plus. As soon
as you do, stop – you may have 1 strip
of 1 colour left over.
Sit the rolled cake on one of its flat
ends if you haven’t already. Spread
a good layer of orange frosting over
the top, then press on 1 of the round
chocolate sponges (see step G in the Guide) – line it up to the
middle of the roll, rather than one of
the edges of the roll. This means you’ll
have to take a sharp knife and trim
the roll all around, until it is perfectly flush with the round sponge top.
Flip the cake upside down onto your
serving plate. Spread some more
orange frosting over the new top,
and add the second round sponge.
Gradually spoon on, and spread over,
the chocolate icing with a big palette
knife. If should still be runny enough
to gently run down the sides, giving
you a shiny finish (see step H in the Guide).