In a mixing bowl, combine flour and salt. Add cold butter and mix until the mixture resembles coarse crumbs.

Gradually add ice water, mixing until the dough comes together. Divide dough in half, shape into disks, wrap in plastic, and refrigerate for at least 1 hour.

In a large bowl, combine blueberries, sugar, cornstarch, lemon juice, and cinnamon. Toss gently to coat the blueberries evenly.

Preheat the oven to 425?F (220?C). Roll out one disk of dough on a floured surface to fit the pie dish. Place the rolled dough in the dish.

Fill the crust with the blueberry mixture and dot with butter. Roll out the second disk of dough and place over the filling. Seal and flute the edges. Cut slits in the top crust for steam to escape.

Bake in the preheated oven for 45-50 minutes, or until the crust is golden brown and the filling is bubbling. Let cool before serving.