Choose the mold you prefer, even the classic one is very nice, but I recommend spraying it with the release spray even if it is silicone like mine; it will allow you to unmold it easily and well defined.
Chop or grate the chocolate.
In a bowl, dissolve the cornstarch with a ladle of milk; then add the rest of the milk and the sugar.
Pour into a saucepan and bring to a boil. Turn off and melt the chopped chocolate inside.
Add the butter cut into pieces. Mix well and pour into the mold greased with the non-stick spray.
Let it cool to room temperature and then place in the refrigerator for a few hours.
