Pecan Pie Pastry Sandwiches

In a large saucepan, whisk together brown sugar and cornstarch; whisk in egg yolks, half-and-half, corn syrup, and salt. Bring to a low boil over medium-high heat, whisking frequently; cook, whisking constantly, until thickened and slightly translucent, 2 to 3 minutes. Remove from heat; whisk in butter and vanilla until butter is melted and well combined. Stir in pecans. Cover and refrigerate until cold, about 2 hours.

Line a baking sheet with parchment paper.

Turn out Pastry Dough onto a lightly floured surface, and roll to ⅛-inch thickness. Using a 2¼-inch round cutter, cut dough, and place on prepared pan. Reroll and cut scraps once. Using a fork, lightly dock center of rounds. Freeze until firm, at least 15 minutes.

Preheat oven to 400°F (200°C).

In a small bowl, whisk together egg and 1 tablespoon (15 grams) water; brush onto dough.

Bake until lightly browned, 12 to 15 minutes. Let cool on pan for 10 minutes. Remove from pan, and let cool completely on a wire rack.

Spoon filling into a pastry bag, and cut a ¼-inch opening in tip. Pipe filling onto half of rounds (about 2 teaspoons or 10 grams each). Top with remaining rounds, shiny side up. Roll edges in pecans. Refrigerate in an airtight container for up to 3 days.

In the work bowl of a food processor, pulse flour and salt until combined. Add cold butter; pulse until butter pieces are quarter-size. With processor running, add ½ cup (120 grams) ice water in a slow, steady stream just until dough comes together. (Mixture may appear crumbly but should be moist and hold together when pinched.) Add more water, 1 tablespoon (15 grams) at a time, as needed.

Turn out dough, and divide in half. Shape each portion into a rectangle. Wrap each in plastic wrap, and refrigerate for 1 hour.