Put the milk in the TM with the butterfly. Set to 10 minutes speed 3 at 90C.
Mix the corn starch, sugar, and salt in a small bowl. Slowly add this mixture to the milk through the hole in the lid.
Around minute 8, the pudding should be thickening and the temperature at 90C. Slowly add the chocolate through the hole in the lid.
Just before the end of the 10 minutes, add the vanilla through the hole in the lid (leaving just enough time for the vanilla to mix in). The pudding should be nice and silky.
Pour into 4 (or 6) individual pudding cups.
Place in refrigerator to chill (about an hour). NOTE: To avoid a skin, top the pudding with plastic as soon as possible, right on the pudding. If you like a skin, cover the bowl with plastic, leaving an air space between the plastic and the pudding.