Boil the water with the cinnamon for 5 minutes. Add the chocolate and let it melt, stirring occasionally.
In a bowl, dissolve the corn flour with the 200 ml of water until you get a slightly viscous mixture (if necessary, you can add more water when the consistency is too thick).
Add the sweetener of your choice, we used agave syrup.
Finally, bring the chocolate-cinnamon mixture to a boil and gradually add the corn flour mixture, stirring constantly. Cook until thickened. Enjoy hot.