Purée the chestnuts.
Melt the chocolate using bain-marie method, add butter and let melt, stirring continuously.
Add the sugar, the butter mixture, chocolate and grappa to the chestnut purée, mix well to obtain a smooth mousse.
Fill the minicups (delicious also the chocolate ones) with the chestnut mousse.
Cool for at least an hour and serve.
Upon serving, garnish with a cherry or beat the cream slightly, put in the center and sprinkle with dark chocolate shavings.
Enjoy a flute of wood-aged grappa with your mousse!
