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

Stir in ice water, a tablespoon at a time, until the dough comes together. Divide into two balls, flatten 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 combine.

Preheat the oven to 425°F (220°C). Roll out one disk of dough on a floured surface and fit it into the pie dish.

Fill the crust with the blueberry mixture and dot with butter. Roll out the second disk of dough and place it over the filling. Seal and flute the edges.

Cut slits in the top crust for steam to escape. Bake for 45-50 minutes or until the crust is golden brown and the filling is bubbly.

Cool on a wire rack before serving.