#Fresh raspberry purée flavours a Bavarian cream, sandwiched between rounds of sponge cake, and served with a kirsch-flavoured custard. When raspberries are not in season you can use frozen berries, though they lack the perfume of fresh# Make The Sponge Cake Rounds: Heat the oven to 220° C (425° F, Gas 7). Brush the cake tin with melted butter. Line the bottom with a round of parchment paper and butter the paper. Sprinkle in about 30-45 ml (2-3 tbsp) flour and turn and shake the tin to coat it evenly.

Melt the butter in a small pan and let it cool. Meanwhile, sift the flour and a pinch of salt into a bowl.

Put the eggs in a separate large bowl and beat a few seconds just to mix. Beat in the sugar.

Beat at high speed until the mixture leaves a ribbon trail when the beaters are lifted, about 5 minutes. “You can use a balloon whisk instead of the electric mixer, but heat will be needed to achieve volume. Set the bowl over a pan of hot, not boiling, water, and whisk vigorously, about 10 minutes.”

Sift about one-third of the flour mixture over the egg mixture and fold them together as lightly as possible. Add the remaining flour in the same way in 2 batches.

Just after folding in the flour, pour in the cooled melted butter and fold it in gently but quickly. “Pour melted butter in a thin, steady stream while folding it in with the rubber spatula.”

Pour the batter into the prepared cake tin and tap the tin on the work surface to level the batter and knock out air bubbles. Bake at once near the bottom of the heated oven, until the cake has risen and is just firm to the touch, 20-25 minutes.

Turn out the cake onto the wire rack. Let cool, then carefully peel off the lining paper from the base of the cake. "Hold cake tin and wire rack together firmly"

Cut a thin slice from the top and bottom of the cake to remove the browned and marked portions; discard.

Cut the cake horizontally in half, using the serrated knife.

Trim the cake rounds to fit the Springform tin, using the base of the tin as a guide.

Lightly oil the bottom and side of the springform tin. “It is best to use a good-quality stainless steel tin for making this cake, to avoid discolouring the Bavarian cream filling. To be extra sure, you can line the tin with clingfilm.”

Put one cake round in the bottom of the tin and sprinkle it with 15 ml (1 tbsp) of the kirsch. Set aside while making the Bavarian cream. TAKE CARE: Prepare the cake and tin in advance to be ready for the Bavarian cream because it sets quickly "Sprinkle cake evenly with kirsch" #Make the Raspberry Bavarian Cream# Pick over the raspberries and set aside about one-quarter. Purée the rest in the food processor or in a blender, then work the puréed fruit through the sieve to remove the pips. There should be 375 ml (12 fl oz) of purée. Stir in 15 ml (1 tbsp) of the kirsch with 100 g (3 1/2 oz) sugar, or more to taste. "Purée raspberries for Bavarian cream all at once"

Pour the cream into a chilled bowl and whip until it forms soft peaks and just holds a shape.

Put the milk in a medium saucepan. Split the vanilla pod, if using, and add it to the milk. Bring just to a boil. Remove the pan from the heat, cover, and let stand in a warm place, 10-15 minutes. Remove the vanilla pod from the milk. Rinse the vanilla pod and store to use again.

Set aside one-quarter of the milk. Stir remaining sugar into the hot milk in the pan, until dissolved.

Beat the egg yolks with the cornflour in a medium bowl. Add the sweetened hot milk and whisk until the mixture is smooth. TAKE CARE: Do not overwhisk or the finished custard will be frothy instead of smooth.

Pour the egg yolk and milk mixture back into the saucepan and cook over medium heat, stirring constantly with the wooden spoon, until the custard comes just to a boil and is thick enough to coat the back of the spoon. Stir in the reserved milk and the vanilla essence, if using. “When the custard is thick enough, your finger will leave a clear trail across the back of the spoon.”

Strain the custard into 2 medium bowls, dividing it equally. Let cool until tepid, then stir 30 ml (2 tbsp) kirsch into one half. Set this kirsch custard aside to serve with the finished dessert.

Sprinkle the gelatine over the water in a small saucepan and let soften, about 5 minutes. Set the pan over low heat and shake it occasionally until the gelatine is melted and pourable, 1-2 minutes; do not stir. Stir into the bowl of unflavoured custard. "Stir melted gelatine into custard with rubber spatula"

Pour the raspberry purée into the unflavoured custard, stirring gently until evenly mixed.

Set the bowl in a large bowl of iced water. Stir the mixture until it starts to thicken. Remove the bowl from the iced water immediately.

Fold the raspberry custard into the whipped cream.

Pour half of the Bavarian cream into the prepared cake tin.

Sprinkle the reserved whole raspberries on top, saving 8 for decoration. Pour the remaining Bavarian cream over the berries. "Raspberries will sink a little into the cream"

Evenly sprinkle the remaining 15 ml (1 tbsp) kirsch over the second cake round. "Sprinkling with kirsch ensures that cake round will be moist"

Lightly press the cake round, sprinkled-side down, on the cream. Cover with cling film and refrigerate until firm, at least 4 hours. “Putting the kirsch-sprinkled side of the cake on the Bavarian cream ensures the flavour is absorbed by the cream." #Unmould And Decorate The Cake# Take the cake from the refrigerator, uncover, and remove the side of the tin. Transfer the cake to a serving plate. “Use a large pie slice to help move the cake off its base.”

Make the Chantilly cream: pour the cream into a chilled bowl and whip until soft peaks form. Add the kirsch and sugar to taste and continue whipping until the cream forms stiff peaks. Using the palette knife, spread some of the Chantilly cream over the top of the cake.

Put the remaining Chantilly cream into the piping bag and pipe it decoratively on the top of the cake. #TO SERVE#

Decorate the top of the cake with the reserved raspberries and the mint, and serve the kirsch custard sauce separately. "Raspberries and mint sprigs decorate Bavarian cake"