Blueberry Pie with Shattering Crust

Instructions:

1. Whisk together the all-purpose flour, salt, and granulated sugar in a large mixing bowl.
2. Use a pastry cutter to work the chilled, cubed butter into the flour mixture until it resembles coarse crumbs with some pea-sized chunks remaining.
3. Gradually add ice water, one tablespoon at a time, stirring with a fork until the dough just begins to clump together.
4. Divide the dough into two discs, wrap in plastic, and refrigerate for at least 2 hours to prevent shrinking during baking.
5. In a large bowl, whisk together the coconut sugar, cornstarch, ground cinnamon, and salt.
6. Toss the blueberries with the dry filling mixture, lemon juice, and lemon zest until evenly coated.
7. Roll out the dough, fill the pie plate with the blueberry mixture, and top with the second crust.
8. Beat the egg with water to create an egg wash, brush over the crust, and sprinkle with coarse sparkling sugar.
9. Bake for 60 minutes or until the crust is golden brown and the filling is bubbling.