How to make
Grind the walnuts in a chopper, but not too fine, so that you can still feel the pieces. Do the same with the biscuits.
In a bowl, pour the walnuts and biscuits, heat the butter in a water bath and add it to the dry ingredients, mix it with rum, vanilla and cocoa.
Form the resulting mixture into a roll and roll it in powdered sugar.
Wrap it in foil and leave your sweet salami in the freezer for 3-4 hours to harden.