Many supermarkets sell caterpillar cakes. Sally and I created our own for a book we are writing. There are two variations: a brilliant green lemon curd caterpillar or a beautiful raspberry pink one.
Makes a swiss roll 33 cm long
The basic cake
4 large eggs, 100 g caster sugar, 100 g self-raising flour
The green cake: Zest of 1 lemon finely grated, green food paste, 4 tablespoons lemon curd
The pink cake: Pink food paste, 4 tablespoons raspberry jam
Decoration
85 g unsalted butter, softened, 150 g icing sugar
For the green cake: Juice of 1 lemon, green food paste, Smarties, chocolate buttons, chocolate flake
For the pink cake: Raspberry jam, pink food paste, raspberries, Smarties, white chocolate buttons
Making the cake
Pre heat the oven to 220 C / 425 F / Gas 7
Grease a 33 x 23 cm swiss roll tin and line with baking parchment, cutting the paper so it fits exactly into the corners.
Put the eggs and sugar (and lemon zest if using) into a large bowl and mix with an electric mixer until the mixture develops bubbles and thickens, leaving a trail a bit like that from a snail. Add the coloured food paste till the mixture is a shade you like.
Sift the flour and add, a spoonful at a time, mixing it in very gently with a metal spoon so that you don’t break too many of the air bubbles.
Pour the mixture into the tin, spread it so it goes right into the corners and put into the oven. Cook for about ten minutes. The cake will pull away from the edges and be slightly springy when it is ready.
This next part sounds hard, but is actually very easy; take a wire rack and on top of it put another sheet of baking parchment, a little larger than the cake tin. Put these on top of the cake (paper next to the cake). Grasp the two sides firmly and turn everything upside down. Remove the tin and gently peel away the layer of baking parchment (which was under the cake and is now on top). Trim the edges so they are straight and cut a shallow line 2 cm in from the longest side. This will make it easier to roll up but be careful not to cut right though the sponge.
When the cake is nearly cool spread the jam or lemon curd evenly over it.
Using the baking parchment, roll the cake up lengthwise, as tightly as you can. Leave the paper round the roll as it cools to hold it in place.
Once the cake has cooled you can transfer the cake to a plate or board and gently roll it and remove the paper. You may find there are cracks but they don’t matter as the whole cake will be covered with icing.
Decorating the cake
Put the butter and icing sugar into a large bowl and mix together with a wooden spoon. Add the lemon juice or jam and coloured paste until it tastes and looks exactly how you want. You can have a subtle, realistic caterpillar or a bright lurid one, as you like.
If you want a twisty caterpillar, cut the swiss roll into diagonal chunks and reassemble the opposite way round.
Spread the icing over the whole cake and then decorate as you like. Smarties make good eyes, chocolate flake is good for the eyebrows and mouth and large chocolate buttons are perfect for feet. Remember caterpillars have a lot of feet. You can decorate the body with raspberries or more Smarties.