Crust

• Put butter into freezer 15 minutes ahead of time. In a large bowl, mix together flour, sugar and salt. Using a pastry cutter or two forks, cut in the butter until the mixture resembles pea-sized crumbs. Drizzle water over the dough and bring together (add 1 more tablespoon of water if dough seems dry.) gently knead the dough a few times in the bowl until it all comes together. It is important not to handle the dough too much. Flatten the dough into a disk, wrap tightly in plastic wrap and cool in the refrigerator for 1 hour.
• Preheat oven to 190°C (375°F). Line a large baking sheet with parchment paper or a silicone baking mat. Set aside.
• On a lightly floured work surface, roll the dough into approx 40 x 30 cm (15 x 11 inch) rectangle. If desired, trim the rims of the to make a clean edge. Transfer dough to the prepared baking sheet.
• In a small bowl, combine brown sugar with the ground almonds, flour, and cinnamon.
  Spread this mixture evenly over the dough to within 5 cm (2 inches) of the edge.
• Arrange the plum wedges and gently fold the edges of the dough over the filling, overlapping the dough as necessary. Press gently to seal the edges. Brush the crust edges with egg wash and sprinkle the crust and filling with granulated sugar (and with sliced almonds desired).
• Bake until the filling is bubbly and the crust is golden brown, about 30-35 minutes. Cool on the baking sheet for 10 minutes before slicing and serving. Tastes wonderful served warm with vanilla ice cream.