Strawberry fraisier with mousseline cream

Separate the egg yolks from the whites. Split the vanilla and heat the milk with the seeds and pod. Whisk the yolks with 80 g of sugar and cornflour. Remove the pod, gradually whisk in the milk and return to the heat. Boil for 1 minute while whisking. Spread in a shallow dish and cover the surface. Cool slightly, then refrigerate for at least 120 minutes. Make the sponge meanwhile.

Melt the small butter portion reserved for the sponge and cool until lukewarm. Heat the oven to 180 °C and line a 18 cm tin. Whisk the eggs with 90 g of sugar over a water bath to about 45 °C, then off the bath until cool and forming a thick ribbon. Fold in the sifted flour. Mix a little batter with 20 g of melted butter and fold back in. Bake for about 25 minutes until a skewer comes out clean. Unmould and cool on a rack.

Boil the water with 30 g of sugar and cool. Bring the custard and 150 g of butter out of the fridge to reach a similar temperature, about 20 minutes: the butter should be soft, not melted. Whisk the butter until pale. Smooth the custard and gradually beat it into the butter until silky.

Cut the cold sponge into two equal-thickness layers. Put the lower layer inside the acetate-lined ring and brush with half the syrup. Wash, dry and hull the berries. Stand halved berries against the ring, cut sides out. Spread cream between the berries and over the sponge and put the remaining chopped berries in the centre. Keep a thin layer of cream for the top. Add the upper sponge, brush with the remaining syrup and smooth over the reserved cream. Refrigerate for at least 240 minutes before removing the ring and acetate.