Place half the blueberries, sugar, cornstarch (or all-purpose flour or tapioca), and salt in a small pot and toss to combine.

Tie the apple core & peel and lemon peel & seeds in a piece of cheesecloth, and add to the pot.

Place the pot over medium-low heat and cook, stirring, until the berries have released their juices and the mixture is syrupy.

Remove from the heat and stir in the lemon juice, then allow to cool.

When the blueberry pie filling has cooled, stir in the remaining uncooked blueberries.

Roll half the pie dough out to about 3 inches wider than the pie pan, and transfer the filling to the pie dish.

For a double crust or lattice-top pie: Roll the second half of the pie dough out to about 3 inches wider than the pie pan.

For a crumb-topped pie: Top with streusel crumb topping.

For a double crust or lattice-top pie: Brush with egg wash, and sprinkle with clear sparkling sugar.

Place the unbaked pie in the refrigerator and preheat the oven to 425 degrees F.

Bake the pie for 20 minutes at 425 degrees F, then lower the oven temperature to 350 degrees F and bake until evenly browned and bubbling (approx. 45 to 55 minutes).