Ingredients:
500 ml of milk (whole or semi-skimmed)
50 g cocoa powder
3 egg yolks
50 g sugar (or sweetener to taste)
1 tablespoon cornstarch
A pinch of salt
Cinnamon stick (optional)
Preparation:

Heat the milk: In a pan, heat the milk together with the cinnamon stick (if using). Remove from heat before boiling.
Mix dry ingredients: Mix cocoa powder, cornstarch, sugar, and salt in a bowl.