Concord Grape Tart

Ingredients

For the Pate Brisee Extra:

• 2 ½ cups unbleached all-purpose flour, plus more for dusting
• ¼ cup granulated sugar
• ¾ teaspoon kosher salt
• 2 sticks (1 cup) cold unsalted butter, cut into pieces
• 1 large egg yolk
• ¼ cup ice water

For the Filling:

• ¾ pound Concord grapes, stems removed
• ½ cup plus 1 tablespoon water
• ½ cup plus 2 tablespoons granulated sugar
• 1 ½ teaspoons fresh lemon juice
• ¼ teaspoon kosher salt
• 1 tablespoon cornstarch

For the Assembly:

• 1 large egg, lightly beaten
• Coarse sanding sugar, for sprinkling
• Creme fraiche, for serving

Instructions

1. 1
   Pate Brisee Extra: Pulse flour, granulated sugar, and salt in a food processor to combine. Pulse in butter until mixture resembles coarse meal, about 10 seconds. With machine running, add egg yolk and ice water in a slow, steady stream just until dough holds together. Divide dough in half; shape each half into a flat disk and wrap in plastic. Refrigerate at least 1 hour and up to 2 days.
2. 2
   Filling: Bring grapes and 1/2 cup water to a simmer in a saucepan, mashing occasionally with a potato masher, until fruit is very soft. Strain through a fine-mesh sieve into a heatproof bowl.
3. 3
   In a large, heavy-bottomed pot, combine grape juice, granulated sugar, lemon juice, and salt. In a small bowl, stir together cornstarch and remaining 1 tablespoon water. Add to juice mixture and cook, stirring frequently, until it reads 221 degrees on a candy thermometer. Transfer to same heatproof bowl; let cool completely, stirring occasionally. Filling can be refrigerated in an airtight container up to 1 month.
4. 4
   On a lightly floured surface, roll out each disk of dough to a 1/8-inch-thick round. Transfer one round to a parchment-lined baking sheet. Fit remaining round into a 9-inch round fluted tart pan with removable bottom; trim flush with rim. Freeze both rounds until firm, about 15 minutes.
5. 5
   Using the wide base of two pastry tips (3/4 inch and 1 inch), cut clusters of holes in dough round on baking sheet to resemble a bunch of grapes. Using a sharp paring knife, cut a stem at the top. Return to freezer until firm.
6. 6
   Assembly: Preheat oven to 375 degrees. Spread filling over dough round in tart pan. Whisk together egg and 1 tablespoon water. Brush edges of dough with egg wash. Slide remaining dough round on top, centering the design. Press edges to seal, and trim excess dough. Brush with egg wash and sprinkle with sanding sugar. Place tart pan on a baking sheet.
7. 7
   Bake 30 minutes, then remove from oven and gently tap sheet on counter to release any air bubbles. Continue baking until golden brown and bubbling, 15 to 20 minutes more. Transfer sheet to a wire rack; let cool completely. Unmold tart; serve with creme fraiche.