- 2 ½ oz all-purpose flour
- 2 ½ oz potato starch
- 5 oz sugar
- 6 eggs
To make sponge cake, whisk the eggs and sugar in a mixer until firm.
Then gently fold in, little by little, the flour and potato starch, sieved together, using a spatula.
Once the mixture is smooth, pour it into 2 cake tins, that have been buttered and floured; then bake at 325° F for 45 minutes.
Once cooked, allow the sponge cakes to cool.
While the sponge is in the oven, make the Chantilly cream, by mixing the whipped cream with confectioner’s custard. See below on how to make the confectioner’s custard.
Whip the cream with the powdered sugar, then put it in the refrigerator.
Make the confectioner’s custardas follows.
Cut the vanilla pod lengthwise, scrape out the seeds and put them in a bowl.
Using a potato peeler, take the zest off a lemon, being careful not to take any of the white part underneath. In a pot, bring the milk to the boil with the vanilla seeds and the lemon zest.
As soon as the milk starts boiling, remove from heat.
In a bowl, whisk the eggs and yolks with the sugar.
Add the flour, previously sieved, and mix well.
Once the mixture is smooth, dilute it with a bit of warm milk, stirring while adding. Pour the remaining milk through a sieve to remove the lemon zest.
Put back the mixture over the heat and cook over a low heat for 5 – 10 minutes stirring continuously, allowing it to boil for 2 – 3 minutes.
Remove the custard from the heat and allow it to cool.
Once the confectioner’s custard is cold, fold it in the whipped cream.
To make the syrup, to be used to soak the sponge. Bring to boil a mixture of water and sugar so that the latter dissolves. Once dissolved, remove from the heat and add some Kirsch.
When all the ingredients are ready, assemble the cake as described below.
Cut one sponge into horizontal layers about 0.4 inches thick.
Line a glass bowl about 8 inches in diameter with bands of baking paper. Arrange a layer of sponge on the bottom of the bowl.
Using a small brush soak the sponge with the Kirsch syrup.
Spread a layer of Chantilly cream on top of the sponge and cover with another slice of sponge. Repeat the operation for 3 sponge layers. Then, put the cake in the refrigerator and allow it to rest for 30 minutes or so.
Cut the second sponge into dices 0.2 – 0.4 inches in size.
Turn out the cake onto a plate.
Coat the outside of the cake with the remaining cream.
Spread the sponge dices over the top of the cake to cover the entire cake.