Here, a whisked egg sponge cake is split and deeply filled with strawberries and a luxurious kirsch flavoured crème mousseline – crème pâtissière (pastry cream) enriched with butter instead of whipped cream. The top is finished with a thin layer of marzipan and piped chocolate decorations.
- For the sponge:
- 4 medium free-range eggs, at room temperature
- 125g caster sugar
- Finely grated zest of 2 unwaxed medium lemons
- 125g self-raising flour
- 50g unsalted butter, melted and cooled
- For the crème mousseline:
- 600ml milk
- 1 vanilla pod, split open
- 4 large free-range eggs, plus:
- 2 egg yolks, at room temperature
- 180g caster sugar
- 1tbsp kirsch
- 100g cornflour
- 150g unsalted butter, at room temperature, diced
- For the syrup:
- 75g caster sugar
- Juice of 2 medium lemons, strained
- To assemble:
- About 600g medium strawberries
- 200g marzipan
- 200g dark chocolate, melted
- 1 x 23cm springclip cake tin or loosebased, deep round cake tin, greased, floured and the base lined with baking paper; a strip of acetate to fit inside the tin; a large piping bag fitted with a 2cm tube
Preheat the oven to 180°C/350°F/gas 4. To make the sponge, put the eggs, sugar and lemon zest into a large heatproof bowl set over a pan of simmering water. Whisk using a hand-held electric mixer until the mixture has more than doubled in volume and become very thick, pale and mousselike. To check that the mixture is at the right stage, lift the beaters from the bowl – the mixture that falls off should leave a distinct ribbon-like trail on the surface.
Sift two-thirds of the flour onto the mixture, then gently fold in with a metal spoon. Add the remaining flour and fold in gently to retain as much air as possible, but make sure all the flour is incorporated.
Gently fold in the melted butter.
Pour into the tin and bake for 25–30 minutes until pale golden brown and the sides of the cake shrink away from the tin.
Cool the sponge in the tin for 5 minutes, to allow it to firm up a bit, then carefully turn out onto a wire rack (the sponge is delicate).
Leave to cool while you wash the tin.
To make the crème mousseline, bring the milk and vanilla pod just to the boil in a wide saucepan. Remove from the heat and leave to infuse for 10 minutes. Meanwhile, whisk together the eggs, egg yolks, sugar, kirsch and cornflour in a bowl just until smooth and creamy. Remove the vanilla pod from the milk, then pour through a sieve onto the egg mixture, whisking well. Pour the mixture into the washed saucepan, set over medium heat and stir constantly until the mixture boils and thickens; this will take about 4 minutes. It’s important to keep stirring to avoid the custard going lumpy.
Keep stirring for a minute over the heat to make sure the mixture will be thick enough to pipe, but take care that it doesn’t catch on the bottom of the pan. Stir in the butter.
Allow to cool slightly, then pour into a shallow dish. Press a disc of dampened greaseproof paper onto the surface, to prevent a skin from forming, then chill for at least 1 hour until cold and set firm.
To make the syrup, put the sugar, lemon juice and 70ml water into a small pan and heat gently until the sugar has completely dissolved, then boil for 2 minutes. Remove from the heat and cool.
Roll out the marzipan on a worktop lightly dusted with icing sugar to make a thin disc 23cm across. Keep chilled until needed.
When ready to assemble the cake, slice the cold sponge in half horizontally to make 2 thin, even discs. Place the strip of acetate around the inside of the tin so it will fit snugly between the side of the tin and the sponge (or line the tin with clingfilm or parchment-lined foil). Set one sponge disc, cut side up, in the tin and brush liberally with the syrup. With the back of a spoon, gently squash the edges of the cake down so that they are pushed directly against the sides of the tin.
Choose 12 strawberries of the same height and cut them vertically in half. Arrange pointed end up on top of the sponge layer, cut side against the acetate, making sure the berries are fitting snugly next to each other.
Spoon about two-thirds of the crème mousseline into the piping bag to start off with. Pipe a spiral over the sponge base in the tin to cover completely; pipe between the strawberries to fill all the gaps. (Add the remaining crème mousseline to the piping bag when there is space.) Set 3–5 strawberries aside for the decoration, then quarter the rest. Spread these over the crème so it makes the filling about 2.5cm higher.
Pipe another spiral of crème on top of the berries and smooth level with a palette knife.
Set the other disc of sponge on top, cut side up, and brush with the rest of the syrup.
Gently press the top sponge layer down onto the crème so the assembled cake is firmly pressed against the acetate all round. Lay the marzipan disc on top, then chill well.
Make some decorations from the melted chocolate. To serve, remove the acetate-wrapped cake from the tin, then gently remove the acetate. Set the cake on a plate and finish with the reserved strawberries and chocolate decorations.