Prepare the Chocolate Mixture: In a saucepan, melt the margarine. Add the almond drink (or any milk of your choice), powdered sugar, cocoa, and a pinch of salt. Mix well until everything is homogenized and the cocoa is fully dissolved.
Add Chocolate and Nuts: Turn off the heat and add the couverture chocolate to the saucepan, allowing it to melt into the mixture. Once slightly cooled, add the walnuts.
Combine with Cookies: Break the digestive cookies into smaller pieces and add them to the chocolate mixture. Mix well to ensure all pieces are coated.
Form the Trunk: Lay out a piece of parchment paper and transfer the mixture onto it. Shape the mixture into a log, then wrap tightly with the parchment paper. Secure further by wrapping in cling film.
Chill: Refrigerate the chocolate trunk for 3-4 hours until it is firm.
Serve: Once set, remove the wrapping, slice the trunk into pieces, and serve. Optionally, dust with powdered sugar before serving.