Heat the milk over low heat until it just comes to a boil. Turn off the heat and add the cinnamon stick. Cover and let steep for 10 minutes.

Remove the cinnamon stick. Return the milk to the stove and bring it back to a gentle boil over low heat.

Add the chopped dark chocolate and stir until the chocolate is completely melted. Let it thicken for a few minutes, then remove from heat.

Pour into two mugs and enjoy.