In a large bowl, mix the butter with sugar until soft and creamy.
Place the chocolate in a heatproof bowl. Sit over a pan of barely simmering water (a bain marie) and allow the chocolate to melt, stirring occasionally.
Allow to cool, then pour the chocolate and rum into the butter mixture.
Incorporate the eggs, one at the time, mixing until well combined with the other ingredients. If you substitute the eggs, simply pour milk into the chocolate salami mixture.
Fold in the broken cookies and mix until combined, then refrigerate for 20min.
Using you hands, mould the mixture into a salame-like log and transfer onto a flat surface covered with parchment paper.
Cover completely and firmly roll it, as if it were a rolling pin, to create a smooth, rounded cylinder.
Dust your hands with a little cocoa powder and then rub 2 tbsp of cocoa over the unwrapped salame to stop it getting sticky.
Transfer the salami onto a square of foil and cover entirely.
Refrigerate for about 4 h, then serve on a large wood board with a knife like the real charcuterie, and let your friends slice it up. Buon Appetito!