Start by breaking the dark or milk chocolate into small pieces and placing them in a heatproof bowl. Set the bowl over a pot of barely simmering water, stirring gently until melted, about 5-7 minutes.

While the chocolate is melting, take the liquorice Catherine wheels and unroll them, cutting into 2-3 cm lengths for spider legs.

To assemble, take one Oreo and place about a teaspoon of melted chocolate on top. Position eight liquorice legs around the chocolate, pressing gently. Sandwich another Oreo on top to create the spider body.

Use the white icing pen to draw two large dots on the top Oreo for the eyes of each spider, followed by smaller dots of black icing in the center.

Place the decorated cookies on a tray and allow them to set in a cool area for about 15-20 minutes.