Preheat the oven to 180C/365F/Gas 4.
Place the golden syrup, molasses sugar and butter into a heavy-based pan over a medium heat and bring to the boil. Reduce the heat and simmer gently for 5-6 minutes, or until the sugar has completely dissolved.
Remove the pan from the heat, add the flour and ground ginger and mix well.
Add the brandy and stir to combine.
Divide the mixture into four equal portions and place onto a greased and lined baking tray (leave enough space between the portions on the tray to account for spreading as they cook).
Transfer to the oven to bake for six minutes, then remove and allow to cool slightly, until just setting but still pliable.
Place two tins a little distance apart and balance (bridge) a wooden spoon across the tins. Gently wrap the pliable brandy snap around the spoon to make a hollow cigar shape and set onto a cool plate. Repeat with the remaining brandy snaps.
For the filling, place the double cream, vanilla seeds, icing sugar, kirsch and 50g/2oz of the blackberries into a large bowl and whip together until thickened and purple from the blackberry juice.
Spoon the blackberry cream into a piping bag, then pipe into each brandy snap to fill up.
Place a blackberry at the end of each brandy snap opening and serve on plates with a spoonful of blackberries alongside.