Prepare masa (see recipe link above). You can also use Masa Instantanza if you wish. Prepare according to the package directions.
In a large bowl, combine the masa, brown sugar, and vanilla until well blended.
To assemble the tamales, place 1/2 cup of the masa in the center of the smooth side of a corn husk. Using the back of a wet tablespoon, make an indentation in the center of the masa and fill with 1 1/2 tablespoons or more of the chocolate chips. Fold both sides of the husk tightly in over the masa mixture and tie a t both ends. Repeat for the reaming tamales. Steam the tamales for 55 minutes. Serve plain or with whipping cream.
The owner of this pot de creme cup describes it as being from the Napoleon III era from the Sevres factory in France