How to Make It
Preheat oven to 425° F. In a large bowl, toss together the blueberries, cornstarch, lemon juice, salt, and 1 cup of the sugar.
Fit one piecrust into a 9-inch pie plate (avoid stretching). Fill with the fruit mixture, mounding it in the center. Top with the second piecrust and press the edges of the crusts together to seal. Trim the crust to a 1-inch overhang, fold the overhang underneath itself, and crimp the edge of the dough. Brush the top crust with heavy cream and sprinkle with the remaining tablespoon of sugar.
Cut several slits in the top of the pie, place the pie plate on a foil-lined rimmed baking sheet, and bake for 20 minutes. Reduce heat to 375° F and bake until the crust is golden and the juices are bubbling, 60 to 70 minutes more. Tent with foil if browning too quickly. Let cool at least 2 hours before serving.