Melt the chocolate in a double boiler. Whisk in the sugar. Gradually add the cream, whisking constantly until smooth; remove from heat. In a medium bowl, vigorously beat the egg yolks. Gradually whisk about one-fourth of the chocolate mixture into the yolks. Add the egg-chocolate mixture back into the pot with the warm chocolate mixture, whisking constantly. Whisk in the vanilla. Spoon into small pots de crème cups or cordial glasses and chill for at least 1 hour. Top each serving with fresh peppermint whipped cream and shaved chocolate.