Start by making the base, blitz the biscuits and add melted butter. Place the mix in a layer at the base of a loose bottom square tin, around 20 centimeters. Place in the fridge to set, at least an hour.
Next, make the chocolate layer. In a heavy based saucepan, melt the butter with the golden syrup and add in the roughly chopped chocolate. Once all melted, break the biscuits and add to the mix. Let this cool slightly and then pour on top of the biscuit base and place back in the fridge whilst you make the caramel layer.
Melt together the butter and the sugar on a medium heat in a medium pan. Once all melted add in golden syrup and condensed milk and bring to a low boil. Once the colour has darkened, leave to cool in the fridge.
Pour the caramel layer on top of the chocolate layer. Roll the berries in icing sugar and place them in the caramel
Randomly. Let this set in the fridge until it's hard.
Melt the topping chocolate, with the knob of butter and let this cool. Once the caramel has hardened, pour over the chocolate topping and cool until hardened. Cut into the desired amount of slices.