Combine the chocolate, 50 grams of heavy cream, and coffee in a bowl, place over a double boiler and melt until completely smooth, then cool to a temperature of 35-40°C.
Beat the remaining sweet cream until stiff peaks form, adding sugar to taste.
Add the chocolate to the whipped sweet cream, gently mix, and fill molds or cups.
Put it in the fridge for at least an hour.
The mousse can be decorated with whipped sweet cream and grated chocolate.
Enjoy!