📋 Instructions

1. 1Make the pastry dough — Whisk the flour, granulated sugar, and 1/2 teaspoon salt in a large bowl, then cut in the cold butter with a pastry blender until pea-sized lumps remain. Stir in the egg yolk and 3 to 4 tablespoons ice water until the dough just holds together when squeezed.
2. 2Chill the dough — Divide the dough in half, flatten into discs, wrap in plastic, and refrigerate for at least 30 minutes (up to 2 days). Cold dough rolls without sticking and bakes up flakier.
3. 3Cook the pumpkin filling — Warm the pumpkin purée, brown sugar, pumpkin pie spice, cornstarch, and a pinch of salt in a small saucepan over medium heat, stirring constantly for 4 to 5 minutes until it thickens and a spoon dragged through leaves a clean trail. Scrape it onto a plate and cool completely.
4. 4Roll and cut rectangles — Heat the oven to 375°F (190°C) and line two sheet pans with parchment. Roll one dough disc on a floured surface to a 1/8-inch rectangle, then cut into six 3-by-4-inch rectangles, re-rolling scraps once.
5. 5Fill and seal — Spoon a scant 1 1/2 tablespoons cooled filling onto the center of each rectangle, brush the border with egg wash, and top with a second rectangle. Press the edges closed, then crimp with a fork and poke three vents in the top.
6. 6Bake until golden — Bake for 22 to 25 minutes, rotating the pans halfway, until the edges are deep golden brown and the filling bubbles faintly at the vents. An instant-read thermometer in the center should read about 200°F (93°C).
7. 7Glaze and sprinkle — Whisk the powdered sugar with the milk and a pinch of salt until smooth and pourable. Spread over the warm tarts, shower with sprinkles, and let set for 20 minutes before serving.