Combine 2 c. water, 1 c. sugar, 1/3 c. cornstarch, and ½ c. blackberries in a pot. Cook until mixture turns thick.

Meanwhile, fill an uncooked pie crust with 2-3 c. of berries then cover with the cornstarch mixture. Place a few pats of butter over filling.

Top with another uncooked pie crust. Seal edges and bake until golden brown—
about 350 degrees.