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  1. Preheat the oven to 425°F. Lightly grease a 9" pie pan that’s at least 1 1/2" deep.

  2. To make the crust: Roll the dough out to a 13" circle. Place in the prepared pie pan. Line the crust with parchment or foil and fill with pie weights. Place the pie pan on a baking sheet and bake for 10 minutes. Remove from the oven and remove the lining and weights. Reduce the oven temperature to 375°F.

  3. To make the lemon filling: Melt the butter and place in a medium bowl. Stir in the lemon juice, salt, sugar, cornmeal, and cornstarch. Mix in the eggs, one at a time, until the mixture is uniform. Pour into the pie shell.

  4. Bake the pie on the bottom rack of the oven for 20 to 25 minutes, until the filling is almost set (it should still wobble a bit in the center when nudged). Remove from the oven and place on a rack to cool a bit while you make the streusel and blueberry filling. The filling will finish cooking as the pie sits. Note: Don't turn the oven off, you'll be using it again.

  5. To make the streusel: In a small bowl, whisk together the flour, sugar, salt, and cinnamon. Melt the butter and add the vanilla; pour over the flour mixture and toss with a fork to form irregular crumbs. Set aside.

  6. To make the blueberry filling: Place the berries in a 2-quart saucepan (if using fresh berries, rinse but don’t dry the berries first). Whisk together the sugar, salt, and cornstarch and stir into the berries. Place over medium-low heat and cook, stirring frequently, until the berries give up their liquid. Bring to a boil, stirring constantly, until the mixture thickens. Remove from the heat and gently spoon the filling over the lemon layer.

  7. Sprinkle the streusel over the blueberry layer and return to the center rack of the oven for 15 to 20 minutes, until the crumbs are lightly browned. Remove from the oven and let cool to room temperature, then chill thoroughly before slicing and serving.

  8. Store covered and refrigerated for up to five days.