These cakes rise a lot during baking, so bake them separately to make sure you get an even rise. The results are completely worth the extra time. And don’t worry if you have a little bit of cracking – the sponge is delicate, so this is to be expected.
Heat the oven to 200°C/180°C fan/400°F/Gas 6. Wrap each of the lined cake tins in a double thickness of foil – this is to prevent water from the water bath soaking into the cake as it cooks.
Make the toadstool cap. Tip the cream cheese into a large heatproof mixing bowl, place over a large pan of simmering water and whisk until smooth. Add the egg yolks, whisking well with a balloon whisk to combine. Add half the sugar and whisk again to combine.
Melt the butter with the milk and double cream either in the microwave or in a small pan. Add this to the cream-cheese mixture with the salt, and the lime zest and juice and whisk to combine. Remove the bowl from the pan of water.
Sift the flour and cornflour into the bowl and use the balloon whisk to mix until smooth.
In the bowl of a stand mixer fitted with the whisk, whisk the egg whites with the cream of tartar until foamy, then add the remaining sugar and continue to whisk until the meringue mixture holds soft peaks. Add one third of the meringue to the cake mixture and use the balloon whisk to mix in until no streaks remain.
Add another third of the meringue and this time fold it in using a large metal spoon. Fold in the final third of meringue in the same way and carefully pour the mixture into the prepared 20cm tin. Gently tap the tin on the work surface to disperse any large air pockets.
Sit the filled cake tin in the middle of a large, deep roasting tin and half fill the tin with boiling water. Bake the sponge, in the water bath, in the bottom third of the oven for 18 minutes, then reduce the oven temperature to 140°C/120°C fan/275°F/Gas 1 and bake for a further 30 minutes. Turn the oven off and leave the sponge inside, without opening the oven door, for 30 minutes. Then, remove the sponge from the water bath and return it to the cool oven, this time leaving the oven door ajar, for another 20–30 minutes.
Carefully remove the sponge from the tin, remove the baking paper and leave to cool on a wire rack. While the first sponge is cooling, prepare the cake for the stalk. Make the batter in the same way, but bake the sponge in the smaller cake tin for 15 minutes at 200°C/180°C fan/400°F/Gas 6 and then reduce the heat to 140°C/120°C fan/275°F/Gas 1 and bake for another 25 minutes. Turn the oven off and leave the cake inside without opening the oven door for 30 minutes, then remove from the water bath and return to the cool oven with the door ajar for another 20–30 minutes, as before.
While the sponges are baking and cooling, prepare the cherry cream. Tip the pitted cherries into a pan, add the caster sugar, the lime zest and juice and 1 tablespoon of water. Cook over a low–medium heat, stirring occasionally, until the fruit is tender and most of the liquid has cooked off. Remove from the heat, add the almond extract and leave to cool.
Whip the cream to soft peaks and fold this into the cold cherry compote. Cover and chill until needed.
To assemble, place the smaller cake on a serving plate and using the larger (6–7cm) cutter, stamp out and remove a cylinder from the middle of the cake (discard the offcut). Fill the cavity with most of the cherry cream, then spread the remaining cream over the cake.
Spray the larger cake layer with red food-colouring spray and leave to dry.
Lightly dust the work surface with icing sugar and roll out the white fondant icing until 2mm thick. Using the smaller cutter, cut out circles of white fondant. Very lightly brush each circle with water and stick the white spots on top of the red cake. Re-roll the trimmings and, using a small, sharp knife, cut out smaller circles for the pupils and ‘glints’ for the eyes, according to the picture. Roll out the black fondant, and again using a sharp knife, cut out circles for the eyes. Using a little water stick the white details onto the black circles, then fix the completed eyes to the cake. Carefully place the red cake on top of the cherry-filled cake to serve.