Mix the milk and cream. Bring to a boil.
Pour the cocoa powder into this hot liquid. Let it dissolve and cool.
In a bowl, mix the egg yolks and sugar.
Pour the cocoa-flavored liquid over the yolks, whisk lightly and refrigerate for 1 hour.
Whisk the cold mixture again and pour it into individual ramekins.
Bake in a water bath for 45 minutes.
Let it cool completely in the refrigerator before caramelizing.