Run a knife along the length of the vanilla pods, scraping out the seeds, and then chop up the pods. Put the seeds and pods in to a thick-bottomed pan with the milk and cream. Simmer slowly for 5 minutes for the flavor to infuse.
In a bowl that will fit into the top of the pan, but not fall into the pan, whisk the egg yolks, sugar, and cocoa powder for a minute. Still slowly whisking, add the vanilla-flavored milk and cream and keep whisking until well mixed.
Add 1-inch (2.5 centimeters) of hot water to the dirty pan bring to a simmer and put the bowl on top of the pan. Cook the custard slowly over the simmering water for 5 minutes, stirring often until it coats the back of the spoon.
Strain the custard through a fine sieve into a clean container. Discard the vanilla pods.
Preheat the oven to 300 degrees F (150 degrees C).
Put 4 ovenproof serving dishes in a high-sided roasting tray. Divide the chocolate between them and shake flat. Carefully divide the custard mix between the dishes; making sure the chocolate isn't disturbed. Fill the tray with water until it is halfway up the sides of the dishes.
Cook in the preheated oven for around 30 to 45 minutes until slightly wobbly in the middle. Allow to cool, then sprinkle with some sugar, and caramelize with a blowtorch.
Propane Gas Torch Warning: Propane gas torches are highly flammable and should be kept away from heat or flame, and should not be exposed to prolonged sunlight. Propane gas torches should only be used in well-ventilated areas. When lighting a propane gas torch, place the torch on a flat, steady surface, facing away from you. Light the match or lighter and then open the gas valve. Light the gas jet, and blow out the match. Always turn off the burner valve to "finger tight" when finished using the torch. Children should never use a propane gas torch without adult supervision.;