Preheat your oven to 120℃, line a baking pan with parchment paper and draw circles starting with 18 cm, 15 cm, 12 cm... until you get to 3 cm. Set aside.
In a clean bowl and with your hand or electric mixer, whip the egg whites while adding the sugar and vanilla gradually. Whip until stiff peaks. Finally, add the white vinegar and whip again until incorporated.
Transfer to a piping bag with nozzle of choice and pipe the meringue in the circles drawn earlier.
Bake in preheated oven for 1 hour or until a bit golden brown and dry. Take out of the oven and let them cool.
Preheat your oven to 200℃. With a knife, cut a cross shape on both sides of each chestnut. Bake in the oven for 30 mins or until the chestnuts' shells begin to open.
While still hot and with a towel (to not burn your hands), peel the chestnuts and transfer them to a saucepan. Add the water, sugar and vanilla. Heat until water has reduced to half.
Transfer the mixture with the water to a food processor and process until smooth. This is your chestnut puree, set aside.
Whip 1 cup whipping cream with your mixer while adding 2 tbsp sugar, 2 tbsp cocoa powder and 1 tsp vanilla gradually. Whip until stiff peaks. Add the pureed chestnuts and mix again until incorporated.
Transfer mixture to a piping bag with a nozzle of choice.
With your hand or electric mixer, whip 1 1/2 cups whipping cream while adding 2 tbsp sugar and 1 tsp vanilla gradually. Whip until stiff peaks.
Start with your largest meringue circle, pipe some chestnut filling on top, put the second largest circle on the chestnut filling and repeat until all meringues are used and you have a mountain of alternating meringues and chestnut filling.
Pipe the whipped cream all over in lines starting with the bottom to the top. Decorate with more chestnuts and enjoy!