Honey-balsamic blueberry pie mound sound unexpected but it's supremely sensational! A touch of tangy sweet balsamic vinegar combined with honey, cinnamon and a pinch of freshly ground black pepper magnifies the sweetness of the blueberries.
For the crust:
Process first four ingredients in a food processor until mixture resembles a coarse meal. With processor running, gradually add 4 tablespoons ice cold water, 1 tablespoon at a time, until dough form into a ball and pulls away from sides of bowl. Add up to 2 tablespoons more water if necessary.
Halve dough and flatten into disks, then wrap in plastic wrap. Chill for 2 hours.
For the filling:
Place 1 cup of blueberries in large bowl, crush with a wooden spoon. Stir in the cornstarch and vinegar until cornstarch dissolves. Stir the remaining filling ingredients into the crushed berry mixture.
Unwrap 1 disk of the chilled dough, and place on a lightly floured surface. Sprinkle with flour. Roll to 1/8-inch thick.2.
Fit dough into greased (with butter) 9-inch deep dish pie plate. Repeat rolling procedure with remaining dough disk, then cut it into 12 to 14 (1/2-inch wide) strips. Remove scraps but do not discard.3.
Pour fruit mixture into piecrust. Dot with butter cubes. Arrange piecrust strips in a lattice design over filling. Trim excess dough.4.
Re-roll remaining dough and cut into six 9-inch by 1/2-inch strips. Twist together 2 strips at a time. Whisk together egg and 1 tablespoon of water. Brush a small amount of egg mixture around edge of pie.5.
Arrange twisted strips around edge of pie, pressing lightly to adhere. Brush entire pie with remaining egg mixture. Freeze 20 minutes or until dough is firm.6.
While pie is freezing, preheat oven to 425 F. Bake pie on a foil-lined baking sheet for 20 minutes. Reduce oven temperature to 375 F, bake 20 minutes more. Cover pie with foil to prevent excessive browning and bake 25 to 30 minutes (about 65 to 70 minutes total), or until crust is golden and filling bubbles in center.7.
Remove from baking sheet to a wire rack and cool for 1 hour before serving.