Start by breaking the biscuits into medium-sized pieces in a large mixing bowl. Thin, crisp biscuits work best for this recipe.
Grind 220g of peanuts in a blender or food processor until they are finely chopped, with no large pieces remaining.
Mix Biscuits and Peanuts:
Combine 120g of the ground peanuts with the crumbled biscuits in the mixing bowl. Set aside the remaining 100g of peanuts for decoration.
Prepare the Cocoa Mixture:
In a small pot, mix together the sugar, cocoa powder, and vanilla sugar.
Slowly pour in the milk while stirring constantly to combine.
Cook the mixture over low heat until it begins to boil, stirring continuously to avoid lumps.
Combine All Ingredients:
Once the cocoa mixture thickens, remove it from the heat and add the butter. Stir until the butter is completely melted and the mixture is smooth.
Allow it to cool for about 10 minutes.
Pour the cooled mixture into the bowl with the biscuits and peanuts. Mix well until the liquid is absorbed and the mixture reaches a batter-like consistency.
Shape and Refrigerate the Roll:
Pour the prepared mixture onto a sheet of baking paper or plastic wrap.
Roll it up tightly into a log shape, making sure the roll is compact.
Refrigerate for a few hours or overnight until it is fully set.