2) Reduce the heat to medium-low and simmer, stirring frequently, until the rice is tender and the mixture thickens, about 35 to 40 minutes. Remove the pan from the heat and discard the vanilla pod.
3) Stir the cocoa powder and orange liqueur into the mixture. Add the chocolate and stir until melted. Allow the mixture to cool for 10 minutes, stirring occasionally.
4) Spoon the rice pudding into serving bowls. Cover and refrigerate for 2 1/2 to 3 hours and up to 1 day ahead.
Inactive prep time: 3 hours