Chill mixing bowl and pastry cutter in freezer for about 15 minutes prior to making crust.
Cut the butter called for in the crust into the flour with a pastry cutter. Slowly incorporate ice water just until the dough begins to form.
Pour dough onto parchment paper, divide and quickly work into two flat discs. Wrap tightly and place in the freezer to chill prior to using.
For the Cobbler:
Combine berries, sugar, butter, and water in a heavy-bottomed pan.
Bring to boil over medium heat and cook for 20 minutes. Berries will be soft when pressed against the side of the pan with a spoon. The blackberry mixture will also begin to thicken and become syrupy.
Preheat oven to 425ยบ F.
Remove pastry for cobbler crust from the freezer and roll. Cut 1/2" strips in both portions of the dough.
In one half of the dough, cut strips again to form individual pieces for dumplings.
Drop the dough pieces into boiling blackberries and occasionally stir gently to make sure all dumplings are cooked, about 7 minutes.
Remove cobbler pan from heat and place the second half of the dough in a lattice pattern on top of the blackberries. Place pieces of butter on top of the lattice crust and sprinkle with sugar.
Place into oven and bake for about 20 minutes or until crust is lightly browned.
Remove from oven and allow to cool for at least 10 minutes before serving.