Linda’s bust of Bob Marley is reinvented in this recipe as a gorgeous ombre cake with shades of orange and yellow buttercream to complement the layered lemon and orange sponges. Coconut-rum-flavoured buttercream is suitably tropical.
Make the lemon curd. In a heatproof bowl using an electric hand whisk, whisk together the sugar, eggs and yolks. Add the lemon juice and zest and whisk again to combine.
Add the cubed butter and place the bowl over a pan of simmering water. Cook, whisking almost continuously for about 10 minutes, until the lemon curd is hot and thickens. Strain into a clean bowl, cover the surface with cling film, leave to cool, then chill until needed.
Heat the oven to 180°C/160°C fan/Gas 4.
Make the lemon sponges. Place the butter and sugar in the bowl of a stand mixer fitted with the beater attachment and beat on medium speed for about 4 minutes, until pale and creamy. Add the eggs, a little at a time, beating well between each addition.
Sift the flour and baking powder into the bowl, add the lemon zest, lemon juice and milk and beat again until the mixture is smooth and the ingredients thoroughly combined.
Divide the mixture equally between the cake tins, spread level and bake for 20–25 minutes, until well risen, golden brown and a skewer inserted into the centres comes out clean. Cool in the tins on a wire rack for 2 minutes, then turn out onto the wire racks, remove the backing paper and leave to cool completely.
Use steps 4–6 to make the orange sponges.
Make the meringue buttercream. Put the sugar, egg whites and salt into a medium heatproof bowl set over a pan of simmering water. Add 2 tablespoons of cold water and, using an electric hand whisk, whisk until the sugar has completely dissolved and the mixture is foamy.
Continue to cook for about 3 minutes, whisking continuously until the mixture is hot to the touch, thickens, starts to increase in volume, turns bright white and holds a firm ribbon trail when you lift the whisk.
Pour the mixture into the bowl of a stand mixer fitted with the whisk attachment and beat on a medium–high speed for 3–4 minutes, until the mixture has doubled in volume and is thick, stiff, glossy, and cold to the touch.
Gradually add the softened butter, whisking continuously until smooth. Add the vanilla and mix again to combine. Spoon into a clean bowl and cover until needed.
Prepare the candied citrus zest. Using a vegetable peeler cut the lemon and orange zest into strips, then slice into fine juliennes.
Tip the sugar into a small saucepan and add 50ml water. Bring to the boil over a medium heat, stirring to dissolve the sugar. Add the citrus zests and simmer over a low–medium heat for 5 minutes, until the zests have softened and become translucent. Strain and leave to dry on baking paper.
Make the coconut-rum cream. Using an electric hand whisk, whip the cream and coconut-flavoured rum together until the mixture holds soft peaks, then set aside.
Once the sponges are cool, assemble the cake. Place 1 lemon sponge on a serving plate and spread with one third of the flavoured cream. Spread over one third of the lemon curd and top with an orange sponge. Repeat the whipped cream and curd layers, top with the remaining lemon sponge and repeat again, ending with the second orange sponge.
Spread the top and sides of the cake with a thin, even layer of buttercream to create a crumb coat and chill for 30 minutes–1 hour.
Meanwhile, divide the remaining buttercream into 5 bowls and tint one bowl orange, the second pale orange, the third yellow and the fourth pale yellow. Leave the fifth white. Spoon all but 2 tablespoons of each coloured buttercream into the piping bags fitted with the medium plain nozzles.
Starting at the bottom of the cake, pipe the orange buttercream around the base and sides, moving up the cake as you do so. Continue with the pale orange, followed by the yellow, pale yellow and then the white so the side and top of the cake are completely covered in the buttercream.
Using a palette knife gently smooth out the buttercream, muddling the colours to ombre the buttercream as you go. Using a smooth cake scraper, smooth the buttercream to give a neat finish.
Spoon half the remaining white buttercream and all the remaining yellow buttercream into a piping bag fitted with a star nozzle and pipe rosettes over the top of the cake. Repeat with the remaining white and orange buttercreams. Scatter the candied citrus peels over the top of the cake to decorate.