1cup240 ml jam or preserves, homemade or store-bought, preferably made with organic fruit
1egg whisked with 1 tablespoon water, for egg wash
Confectioners’ sugar, for dusting
Instructions
To make the tart dough:
In a medium bowl, stir together the flour, sugar, and salt. Cut the butter into small pieces and add it to the bowl. Work the flour mixture and butter together with your hands until the butter is evenly distributed in small bits.
Sprinkle the ice water evenly over the mixture, then work the dough vigorously with your hands until it is fairly smooth. (The dough can also be mixed in a food processor.)
Press the dough into a disk, enclose it in plastic wrap, and let rest for 30 minutes or up to 1 day.
To assemble the “pop tarts”:
While the dough rests, set a rack in the center of the oven and preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.
Roll out the tart dough on a cold, lightly floured surface until it is about ⅛ inch (3 mm) thick. Cut out eight 3 by 5-inch (7.5 by 12-cm) rectangles from the dough, using a postcard or file card as a template.
Use a bench scraper or large spatula to transfer 4 rectangles to the prepared baking sheet, spacing them evenly on the sheet. Spread 2 to 3 tablespoons of jam in the center of each pastry, then top them with the 4 remaining rectangles, lining them up evenly with the bottoms. Press the edges closed with a fork to tightly seal them all around.
To bake, brush the tops with the egg wash, then bake until the tarts are golden brown, about 25 minutes. Sift confectioners’ sugar over the tops and serve immediately.