Instructions

  1. Stir together the sugar, flour, butter and vanilla.
  2. Gently stir in blackberries.
  3. Spoon blackberry mixture into a lightly greased 11 x 7 baking dish.
  4. Cut the piecrust into strips and arrange on top of blackberry mixture.
  5. Mix together the egg white and water.
  6. Brush the pie crust strips with this egg wash.
  7. Sprinkle with sugar.
  8. Bake at 425 for 45 minutes, or until crust is golden brown and blackberries are bubbly.