Method

• 1.
  For the pastry, combine flour, sugar and salt in a bowl. Add butter and toss to coat. Turn out onto a clean work surface and, using a pastry cutter (or flat-bladed knife), roughly cut butter into flour (leaving some large chunks of butter so the pastry will be nice and flaky).

• 2.
  Create a well in the centre of flour mixture and add vinegar water in 3 batches, working it in with your hands to form a rough dough (you may not need all the water). Discard ice. Shape into a disc, wrap in plastic wrap and chill for 3 hours.
• 3.
  Roll out one-third of the pastry on a lightly floured work surface to form a 20cm × 15cm rectangle, 3mm thick. Cut into fifteen 8mm × 20cm strips.
• 4.
  Roll out one-third of the pastry on a lightly floured work surface to form a 20cm × 15cm rectangle, 3mm thick. Cut into fifteen 8mm × 20cm strips.
• 5.
  Cook blackberries, caster sugar, jam and ginger in a pan over medium heat for 15 minutes or until syrupy. Stir 1/4 cup (60ml) syrup with cornflour until smooth. Return cornflour mixture to pan and cook for a further 4 minutes or until thickened. Remove from heat. Cool completely.
• 6.
  Pour the filling into the pastry-lined dish. Make a loose lattice top with the chilled strips and place it over the filling. Press the edges to seal and trim any excess pastry. Freeze for 1 hour.
• 7.
  Preheat oven to 200°C. Brush pastry with egg wash and scatter with demerara sugar. Place on a baking tray. Bake for 30 minutes or until light golden. Reduce oven to 180°C and cook for 30 minutes or until golden.
• 8.
  Rest for 30 minutes. Serve with cream.