PAUL’S CATERPILLAR CAKE

Hooray! A caterpillar cake has come crawling into The Great British Bake Off! This is a chocolate Swiss roll evolved into a gorgeous birthday treat... The question is: what will you call yours?

YOU WILL NEED 33 x 23cm Swiss roll tin, greased, then lined (base and sides) with baking paper ■ 3 small piping bags, each fitted with a small star nozzle ■ Baking sheet, lined with baking paper ■ 7cm round cutter or ring lined with acetate ■ Small flat plate, lined with a disc of baking paper ■ Small piping bag fitted with a small plain writing nozzle

SERVES 8-10 HANDS ON 1 HOUR BAKE 1 HOUR

FOR THE SPONGE

■ 5 large eggs

■ 125g caster sugar, plus extra for sprinkling

■ 80g plain flour

■ 50g cocoa powder

FOR THE MERINGUE DECORATIONS

■ 2 large egg whites

■ 100g caster sugar

■ Green food-colouring paste n Red food-colouring paste

■ Yellow food-colouring paste

FOR THE GANACHE COATING

■ 200g 54% dark chocolate,

chopped

■ 15g unsalted butter

■ 300ml double cream

FOR THE CATERPILLAR FACE

■ 75g white chocolate

■ 50g icing sugar, sifted

■ Black food-colouring paste

■ Cornflour, for dusting

■ 10g red fondant

■ 10g white fondant

FOR THE CHOCOLATE FILLING

■ 200g unsalted butter, cubed and softened

■ 200g icing sugar, sifted n 2tbsp cocoa powder, sifted

Make the sponge

Heat the oven to 220°C/fan 200°C/gas 7. Whisk the eggs and sugar in a stand mixer fitted with the whisk, on high speed for 2-3 minutes, until it is pale, thick and leaves a ribbon trail in the mixture when you lift the whisk. Sift the flour and cocoa powder into the bowl and gently fold it in using a large metal spoon, taking care not to beat any of the air out of the mixture, until combined.

Pour the mixture into the prepared tin and spread it evenly into the corners with a palette knife, if you have one. Bake the sponge on the middle shelf for 10-12 minutes, until it is well risen, firm to the touch, and starts to shrink away from the sides of the tin. Remove from the oven and reduce the temperature to 120°C/fan 100°C/gas ¾.

Place a sheet of baking paper larger than the Swiss roll tin on the work surface and sprinkle with caster sugar. Carefully invert the cake onto the paper and remove the lining paper. Score a line 2cm in from the edge of one of the short sides, making sure you don’t cut all the way through the sponge. Starting from the scored short side, tightly roll up the sponge using the paper to help, then transfer it to a wire rack to cool completely.

Make the meringue decorations

Whisk the egg whites in a stand mixer fitted with a whisk, to soft peaks. A spoonful at a time, add the sugar, whisking to incorporate, then continue to whisk until the meringue is stiff and glossy.

Place half of the meringue in a bowl, add a few drops of green food colouring and fold it in with a metal spoon to an even colour. Divide the remaining meringue between two bowls and colour one batch red and the other yellow. Spoon each coloured meringue into a small piping bag fitted with a small star nozzle. (If you have only one nozzle, then work with one colour at a time, washing the nozzle in between.)

Using the red, yellow and green meringue, pipe 7 small meringue kisses of each colour, about the size of a hazelnut, onto the lined baking sheet. Using the green meringue, pipe six legs in an ‘L’ shape, measuring about 2 x 4cm, and six legs in a reverse ‘L’ shape. Pipe two green curved antennae, each about 4cm long, then use the remaining meringue to pipe flowers to decorate the serving plate or board. Bake the decorations for 45 minutes, until dry. Remove from the oven and leave to cool on the baking sheet.

Make the ganache coating

Put the chocolate and butter in a heatproof bowl and set aside. Pour the cream into a pan and slowly bring it just to the boil. Pour it into the bowl with the chocolate and butter and leave the hot cream to melt them slightly for 1 minute, then stir until smooth and glossy. Leave the ganache to cool and thicken before using.

Prepare the caterpillar face

Melt the white chocolate in a heatproof bowl set over a pan of gently simmering water, stirring until smooth. Place the 7cm cutter in the middle of the lined plate and pour in the melted chocolate, then leave it to cool and set.

Make the chocolate filling

Beat the butter, icing sugar and cocoa powder in a stand mixer fitted with the beater, on low speed for 1 minute, until combined. Increase the speed to high and beat for a further 3 minutes, until pale, creamy and smooth.

Assemble the caterpillar

Unroll the cooled Swiss roll and remove the baking paper. With one of the short sides facing you, make 13 vertical cuts, 1.5cm apart and 15cm long into the sponge, so you now have 14 strips of sponge that look like the keys on a piano. Cut the top of each alternate strip to remove seven sponge fingers (blitz or crumble these to make ‘soil’).

Spread the filling over the sponge and re-roll the Swiss roll tightly from the other (non-cut) short end (the strips will make the ridges on the caterpillar body). Transfer the sponge to a wire rack set over a sheet of baking paper. Carefully pour the thickened ganache over the sponge roll to coat it smoothly, then gently transfer it to a serving plate or board. Arrange the coloured meringue kisses on the ridges of the caterpillar’s body, then set the legs and antennae in place.

Decorate the face

Mix the icing sugar with a few drops of water and the black food-colouring paste to make a thick icing, then spoon it into the small piping bag fitted with the writing nozzle. Remove the set white chocolate disc from the mould.

Dust the work surface with cornflour and roll out the red and white fondants until 3mm thick. Cut out two white ovals for the eyes and roll two tiny white balls for the pupils. Using the red fondant, cut out two circles for the cheeks and a small tongue shape. Dampen the back of the fondant eyes with a little water and press them in place on the white-chocolate face.

Using the black icing, pipe an iris onto each eye, then pipe a mouth. Dampen the fondant cheeks and tongue and stick them in place on the face. Press a white fondant ball onto each iris.

Press the caterpillar face onto the thick end of the Swiss roll — the ganache will help it stay in place. Arrange the meringue flowers and chocolate soil on the serving plate or board, to finish.