Prepare 3 - 4 clean jars and lids with screw caps.
Melt the couverture slowly in a larger bowl over the water bath.
Meanwhile, grind the speculoos and walnuts. Add butter, sugar, condensed milk and spices to the chocolate and stir until everything is melted. Add the ground speculoos and nuts and stir everything well. Fill into the jars while still warm and close the lid.