5cupsplums (about 7 plums), sliced into eighths and left unpeeled
2/3cupsugar
1/4cuporange juice
1egg beaten with 1 tablespoon water
Turbinado sugar (e.g. Sugar in the Raw)
Instructions
In the bowl of a food processor, fitted with the blade attachment, pulse together the flour, sugar, and salt to combine.
Scatter the butter over the flour mixture and pulse until small bits of flour come together. Continue to pulse while adding the water through the feed tube. Keep pulsing until the dough comes together.
Transfer the dough onto a well-floured surface. Bring together any crumbs and form a ball. Divide the dough in half and form each half into a small disc, about 6 inches wide. Wrap each disc in plastic wrap and chill in the refrigerator for at least 1 hour.
To make the filling, mix 3 tablespoons of water with the cornstarch in a small bowl. Set aside.
In a large saucepan, combine the plums, sugar, and orange juice. Cook over medium heat, stirring occasionally, until the juices are released. Stir in the cornstarch mixture. Bring to a boil and then reduce the heat to bring to a simmer. Allow to simmer until the mixture is thickened, about 2 minutes.
Cover the saucepan with the lid and refrigerate until cool, about 30 minutes.
Preheat oven to 425°F and have ready two large sheet pans.
Place parchment paper, the length of each sheet pan, on the work surface.
Remove one dough disc from the refrigerator and place on the center of the parchment paper. Use a rolling pin to roll the disc into a 10 to 11-inch circle.
Lift the parchment paper with the rolled dough and place on the sheet pan.
To the center of the dough, pile on half of the cooled plum mixture, leaving about 1 1/2-inch border all around the dough.
Gently fold the border over the filling, pressing together any cracks. Brush the egg wash on the dough border and sprinkle with turbinado sugar.
Bake for 30 to 35 minutes until border is browned. Allow to cool on pan to room temperature.
Repeat with the second dough disc and remaining filling.