To prepare pastry, lightly spoon flour into dry measuring cups, and level with a knife.
Combine flour and next 3 ingredients (through salt) in a food processor; pulse two times.
Add butter to flour mixture; pulse 4-5 times or until mixture resembles coarse meal.
With processor on, slowly add buttermilk throughfood chute; process just until dough forms a ball.
Gently press dough into a 4” circle on plastic wrap; cover. Chill 30 minutes.
Preheat oven to 340 degrees.
Unwrap and place dough on a sheet of parchment paper. Roll dough into a 15” circle. Place dough and parchment on baking sheet.
To prepare filling, combine berries and next 4 ingredients (through juice) in a medium bowl; toss gently to coat.
Arrange berry mixture in center of dough, leaving a 2” border. Fold edges of dough toward center, pressing gently to seal (dough will only partially cover berry mixture).
Combine fat-free milk and egg white in a small bowl, stirring well with a whisk. Brush dough with milk mixture, sprinkle turbinado sugar evenly over dough.
Bake at 350 for 1 hour or until pastry is golden brown. Let stand 30 minutes; cut into wedges. Yield: 10 servings.