In a saucepan, combine arborio rice, milk, scraped vanilla bean and the vanilla pod. Bring the mixture to a boil, lower the heat to medium low and simmer, stirring frequently, until the rice is tender, about 20 minutes.
Add the sugar, cook till it melts and the mixture thickens a little bit, about 5 minutes.
Remove from heat and stir in the cocoa powder and grated chocolate. Mix well until the chocolate is melted.
Cool for 10 minutes, stirring occasionally. Chill for 2~3 hours before serving and garnish with chopped Baci.
