For the dough

100 g chestnut flour
40 g of cocoa powder
60 of all-purpose flour
200 g of sugar
4 organic eggs
120 g of lukewarm water
80 g of extra virgin Olive Oil Toscano PGI
The zest of 1 lemon
16 g of baking powder
A pinch of salt
A pinch of cream of tartar

For the decoration

250 g of powdered sugar
½ spoon of hot water
1 egg white
2 spoons of sugar
Mint leaves
1 sprig of rosemary
3 boiled chestnuts
3 walnuts kernels

PREPARATION:

Turn on the oven and set the temperature at 150°C (302 °F).

Separate the egg yolks from the whites. Mix the chestnut flour and the all-purpose flour in a bowl, then add the baking powder, the sugar, the cocoa powder, a pinch of salt, the grated lemon zest, the egg yolks, and the extra virgin Olive Oil Toscano PGI previously mixed with the water. Whisk the mixture until you reach a smooth and homogenous texture.
Beat the egg whites until stiff adding a pinch of cream of tartar, and incorporate them gently into the mixture in order not to deflate them.
Pour the mix into a chiffon cake pan, without buttering it, and put it on the oven baking tray lined with parchment paper. Cook for approximately 60/65 minutes in a convection oven.
When the cake is cooked, check it with the “toothpick test”, remove it from oven and turn upside down on a plate, and let it cool for 8 hours, then remove it carefully from the cake pan.
Pour the powdered sugar in a bowl and mix it with a spoon of hot water, add a few more drops of water if needed until you obtain a smooth and soft frosting.
Spread the frosting evenly on the cake.
Decorate the cake with chestnuts, and walnuts kernels. Beat an egg white and the sugar and put the rosemary sprig and the mint leaves in the mixture, then drain them and decorate the cake with them, to obtain a frozen effect.