Melt your butter, chocolate and golden syrup in saucepan over a medium to low heat, stirring to combine. Allow this to cool for 5-10 minutes before adding your rich tea biscuits and mixing well to combine. Fire in your marshmallows mixing through. Then finally in with your Turkish delight mixing this in. Tip this into your baking tray with some greaseproof paper and press it in evenly. Get that into the fridge for a few hours to firm up.