Preheat oven to 400°F.
Combine sugar, flour, cornstarch, and cinnamon in bowl, set aside.
Place wild Blueberries in microwave-safe bowl and microwave on high to thaw. Strain thawed berries, reserving 2 Tbsp. of juice.
Combine dry ingredients and wild blueberries. Stir until mixture is well blended while adding the strained juice.
Pour into a lined 9 inch pie plate. Top with remaining pastry dough and crimp edges. Brush edges and top with cold water. Sprinkle with sugar and vent the top crust.
Bake 40-50 minutes or until filling begins to bubble.