How to make
In a food processor, blend the biscuits into fine crumbs and add the chopped walnuts, sugar, coarsely grated chocolate, melted butter and essence. Knead the mixture well by hand until homogeneous and dough-like.
If necessary, add a little warm water. Moisten your hands, shape small balls and put them to harden for 1 hour in the refrigerator. Melt the chocolate and butter in a water bath for the glaze. Dip each chocolate truffle in it and leave on a cooking grid or tray to harden.
Optionally, roll them in chocolate chips before the glaze hardens completely.