Step 1

In a medium bowl, combine the gelatin and 2 1/2 ounces milk. Whisk with a fork to ensure no lumps remain.

Step 2

In a small sauce pot, combine the sugar, cocoa, salt and remaining milk over medium low heat. Whisk constantly until smooth and the mixture beings to bubble around the edges, about five minutes.

Step 3

Pour the hot dairy mixture through the sieve and into the bowl of gelatin. Whisk the gelatin into the chocolate mixture. Stir in the vanilla, and season with additional salt if needed (I've discovered the amount needed will vary according to the bitterness of the cocoa powder, which varies between brand and type).

Step 4

Set the bowl, uncovered, in the refrigerator. After fifteen minutes cover the pudding with a sheet of plastic wrap pressed against the surface and refrigerate until fully thickened, about 2 hours.

Step 5

To serve: Whip the thickened pudding with a hand or stand mixer for a full minute to restore a creamy texture. (Alas, stirring or beating with a spatula alone will not sufficiently break up the pudding into a creamy, homogenous mixture.) Spoon the whipped pudding into four serving dishes.If all the pudding is not eaten at this time, it will be necessary to re-whip the pudding before serving as prolonged refrigeration creates an unpleasantly firm texture.