In a large saucepan, combine sugar, cornstarch, salt and if desired, cinnamon. And water and stir until smooth; add blueberries. Bring to a boil; cook and stir until thickened, 2-3 minutes. Set aside to cool slightly. Gently fold strawberries, raspberries, blackberries and lemon juice into the blueberry mixture., Preheat oven to 400°. On a lightly floured surface, roll one half of dough to a 1/8-in.-thick circle; transfer to a 9-in. pie plate. Trim even with rim. Add berry mixture; dot with butter. Roll remaining dough to a 1/8-in.-thick circle; cut into 1/2-in.-wide strips. Arrange over filling in a lattice pattern. Trim and seal strips to edge of bottom pastry; flute edge. , Bake for 10 minutes. Reduce oven setting to 350°; bake until crust is golden brown and filling is bubbly, 45-50 minutes. Cool on a wire rack. Store in the refrigerator.