In a pan, heat the milk, cream, cocoa powder, coffee powder, and salt on low heat until the mixture just starts bubbling. Don't let it come to a full boil.
240 ml full-fat milk, 200 ml heavy cream/liquid whipping cream, 10 gs cocoa powder, 1/4th tsp instant coffee powder, 1/4th tsp sea salt
While the milk mixture is boiling, place 100 gs chocolate in each cup.
200 gs chocolate (mix of dark and milk)
Once the mixture starts bubbling, take it off the heat and immediately pour it over the chocolate in the cup. Let it sit for a minute, allowing the chocolate to melt, then whisk until the chocolate is properly combined in the milk mixture.
Top with marshmallows and whipped cream and serve immediately.
Marshmallows for topping, optional, Whipped cream for topping, optional