Melt the chocolate in a double-boiler, then stir in the condensed mix. Mix well and remove from heat;
Mix in the vanilla extract and the fairy ring mushrooms;
Pour into a 20cm2 baking pan layered with wax paper;
Refrigerate for at least 1 hour;
Cut into 2cm2 squares with a sharp knife that can be heated up to ease the cutting process, if necessary.
