How to make
Melt the butter, milk, cocoa and sugar in a container in a water bath. Leave it to cool slightly.
Grind the biscuits and mix them with the walnuts, pinch of salt. Pour the dry mixture into the wet one and stir until homogenized. Then add the rum and rum essence. You can put the mixture briefly in the fridge.
Grab spoonfuls of the mixture and form bonbons using your palms. Optionally, roll them in cocoa, coconut flakes or chocolate sprinkles.