- 1 ½ cup all-purpose flour
- 2 tablespoons sugar
- ½ teaspoon fine sea salt
- 1 stick cold unsalted butter, cubed
- ¼ cup ice water
- 3 cups of fresh blueberries
- ¼ cup sugar
- 1 teaspoon cornstarch
- Zest and juice of small lemon
- 1-2 tablespoons fine cookie crumbs (any crunchy cookie will work)
- 1 tablespoon butter
- 1 egg whisked or 3 tablespoons heavy cream (optional)
- Sparkling sugar (optional)
In a food processor, add flour, sugar, and salt. Pulse to combine. Scatter cubed butter over four mixture and pulse until mixture resembles coarse meal. Drizzle ice water over and pulse until dough just begins to clump. Dump dough out on a clean work surface and bring dough together using your hands to blend any dry pieces into the dough. Shape into an 8-inch round disc of even thickness and wrap in plastic wrap. Chill for at least 45 minutes before rolling.
Preheat oven to 400°F.
Roll dough on a lightly flour surface to about the width of a half-sheet pan. Transfer to a parchment paper-lined sheet pan while you prepare filing.
In a large mixing bowl, add blueberries, lemon zest, and lemon juice. In a small bowl, combine sugar and cornstarch then sprinkle over fruit. Using a large rubber spatula or spoon, toss mixture to the evenly coat.
Sprinkle cookie crumbs in the center of the dough leaving a 2-inch clean border. Mound blueberry mixture over and spread evenly to cover, again leaving a 2-inch border. Lift the dough at the border and press it against the filling. Lift the dough again and repeat, to create a pleated effect around the whole circumference.
Dot the surface with butter. Brush the exposed dough along the border with the egg wash or heavy cream and sprinkle generously with sparkling sugar. Bake in the center rack until the crust is golden brown, about 45-55 minutes. If the crust appears to be browning too browns fast, cover edges with foil. Cool for 30 minutes before slicing. Can be served warm or at room temperature.