Take 2 Tbsp of the milk and form a paste with the cornflour (cornstarch) and set aside.
250 ml whole milk (full fat), 1 tsp cornflour (cornstarch)
Pour the rest of the milk into a small saucepan or milk pan over medium-low heat.
After a minute or so, when the milk is warm (but not simmering), add the dark chocolate, reduce heat to low and whisk to melt the chocolate.
60 g dark chocolate, min 70% cocoa
Add the sugar and sift the cocoa powder over the chocolate drink and whisk to mix.
1 Tbsp white sugar, 1 Tbsp unsweetened cocoa powder
Now, stir the cornflour mix with a spoon to dislodge what's settled at the bottom, and pour it onto the hot chocolate, whisking while doing so, to thicken the hot chocolate.
That's it. You have a homemade Cioccolata Calda. Serve it with some cream or as it is. You can whip the cream if you like, and swirl the top of the hot chocolate with it.