Melt chocolate, butter, vanilla, and condensed milk in slow cooker, when chocolate is melted add rum essence.
Cook on high without lid for 1 hour depending on cooker, stirring every 15 mins.
When fudge is almost cooked add 140g of the raisins and stir through gently. ( reserve remainder for decoration)
Cook further 15 mins
Pour mixture into baking paper lined slice tin
Place reserved raisins on top
Refrigerate for approx 2 hours or until cold and set
Turn out onto board and slice into bite size pieces..... Enjoy!