A decadent, fudgy bake crafted with rich Belgian chocolate and premium inclusions, delivering a dense, melt-in-the-mouth texture.
Place the raisins in a wide bowl with the spiced rum, cover with cling film and place in the fridge overnight or for a couple of hours before. If you don't have time for this, then you can add them both to the recipe, but it helps to not make the cake too wet if the raisins have had some time to absorb the rum.
Grease and line a 20cm/8″ square tin with baking paper.
Put the gingernuts in a ziplock bag and crush them with the rolling pin, leaving some bigger chunks.
Melt the butter, sugar, golden syrup, mixed spice and cocoa together in a large saucepan on the stovetop.
Once the mixture is melted together, remove from the heat and add the biscuits, raisin/rum mix and cranberries, ensuring they are well coated.
Transfer the mixture to your prepared tin and press it down into a compact, even layer with the back of a spoon.
Melt the chocolate in the microwave in 30-second bursts on medium heat, stirring in between. Pour the melted chocolate over the top of the tiffin base, smoothing it out into an even layer by tilting the tray.
Melt the white chocolate and pour in 3-4 lines over the top, then take a skewer or toothpick and use it to swirl the white chocolate into the milk chocolate (optionally, just use all milk chocolate).
Place in the fridge for at least two hours to set.