Prepare the dark hot chocolate and pour into a mug.

Prepare strong coffee or espresso and carefully pour it over the back of a spoon into the mug with the chocolate.

Place the heavy cream and powdered sugar in a bowl and beat with a mixer on high speed until peaks form. Put in a piping bag.

Pipe the whipped cream on top of the coffee. Quickly sprinkle the top with cinnamon and chocolate curls. Serve hot.