Ingredients
Unbleached all-purpose flour, for dusting
14 ounces all-butter puff pastry, such as Dufour, thawed but still cold
1/4 cup light-brown sugar
2 tablespoons cornstarch
1/2 teaspoon kosher salt
1 3/4 pounds ripe peaches (about 5), cut into 1/2-inch wedges
1 tablespoon bourbon (optional)
1 teaspoon pure vanilla extract
1 large egg
Coarse sanding sugar
Vanilla ice cream, for serving
Preparation
Preheat oven to 350 degrees with racks in top and bottom thirds, and a foil-lined rimmed baking sheet on bottom of oven to catch drips.
On a lightly floured sheet of parchment, unfold pastry; roll out to a 10-inch square. Center an 8-inch cake pan upside down on pastry; trace a circle around it with a paring knife. Remove pan; remove and discard excess pastry. Transfer parchment with pastry circle to a baking sheet. Create a crosshatch pattern by scoring lines, 2 inches apart, horizontally and vertically on pastry (do not cut through dough). Refrigerate 5 to 10 minutes.
In a large bowl, whisk together brown sugar, cornstarch, and salt. Add peaches and toss to coat. Stir in bourbon and vanilla. Transfer mixture to a 9-inch pie dish. Cover with parchment-lined foil; bake on lower rack 20 minutes.
Whisk egg with 1 teaspoon water. Brush over pastry circle; sprinkle with sanding sugar. Place baking sheet with pastry on top rack of oven. Bake until pastry is puffed and golden and fruit in dish is bubbling, 35 to 40 minutes (if pastry is browning too quickly, tent with foil). Remove from oven; uncover fruit. Carefully place pastry circle on top of fruit and bake 10 minutes more. Let cool 15 minutes; serve with ice cream.
