Following the list, combine all the ingredients in a saucepan, except for the cookies.
Melt the chocolate slowly, stirring until smooth.
Leave the cream to cool for at least 20 minutes, stirring from time to time. In the meantime, line the mold with plastic wrap (if you want to turn it upside down and serve it on a serving plate) or do not line it at all if you intend to serve the dessert into the mold.
Pour a very thin layer (less than 1/2) of cream onto the bottom of the mold. Arrange a row of cookies, making sure they are not too close together. They must be visible when cut to create a layered effect. For example, when I use a long, rectangular mold, such as a bread mold, I make 3 layers of cookies, using 3 cookies per layer.
Add another thin layer of cream and more cookies. Again, cream and cookies. The last layer of cream, especially if you turn the dessert upside down, should be about 1 cm thick.
Dust with bitter cocoa before serving.
If the dessert is soft, place it in the freezer for 5 minutes. The slices will be perfect.
Refrigerate for several hours or overnight.
You can prepare it several days in advance. You can store it in the freezer or, for a few days, in the refrigerator.