Melt butter and Marshmallows in slow cooker until melted - approx 30mins on high

Add in rice bubbles and coco pops and stir until they are all coated.

Add chocolate and stir in until melted

Add 5-10 drops of black food coloring

Line baking tray with baking paper, grease paper mold mixture to coal shapes. Put in fridge to set.

Decorate by putting in jars/stockings labelled 'coal'