Set aside a few cherries for decoration. Wash and pit the rest of the cherries with a suitable tool. Add the Barolo Chinato, 50 millilitres of water and 50 grams of sugar to a pan and bring to a boil. Add the cherries and cook for 5 minutes. Leave the cherries to cool, then drain, conserving the cooking liquid. 

For the sponge layer, follow the procedure for a standard sponge base, gradually adding the sieved flour and cocoa powder. Mix and pour into a 24 x 30-centimetre mould lined with baking paper. Cook the sponge in a preheated oven at 180° for approximately 20 minutes and then leave to cool. Cut two discs of 18 centimetres in diameter and place one in a ring mould 20 centimetres in diameter and 10 centimetres in height, lined with a strip of acetate. 

Finely chop 150 grams of dark chocolate and melt it in a bain-marie together with the butter cut into flakes. Place the sugar in a pan with 50 millilitres of water and heat the syrup to 121°. Whisk the egg whites in a planetary mixer, pouring the syrup in a thin stream as you whisk. Keep whisking until the whites have cooled. 

Add the cooled melted chocolate and 30 grams of medium-grated chocolate and fold together. Moisten the sponge base with part of the cherry cooking liquid, pour on 2/3 of the mousse mix and add the cooked cherries. 

Cover with the remaining sponge disc, top with the remaining mousse and chill in the fridge for 5-6 hours. Remove from the ring mould, take off the acetate, sprinkle the cake with the remaining grated chocolate and decorate with the cherries previously set aside.