Juicy, caramelized plums combine with fresh lemon zest and a nutty crust in this easy plum tart. Feel free to use walnuts, almonds or hazelnuts in the crust to complement the fruity plum flavor.
Arrange racks in center and lower third of oven; preheat to 425°F . Coat an 11-inch tart pan with a removable bottom with cooking spray. Arrange plums in an even layer on a large rimmed baking sheet. Bake on the lower oven rack, stirring once, until tender, about 15 minutes. Set the plums aside; reduce oven temperature to 375°F.
Place 2 overlapping sheets of plastic wrap on a work surface. Set pastry dough in the center and cover with 2 more sheets of plastic wrap. Roll the dough into a 13-inch circle. Remove the top sheets of plastic and invert the dough into the prepared pan, letting excess dough hang over the edges. Gently press the dough into the bottom and sides of the pan. Pull off plastic wrap. To trim excess dough, run a rolling pin over the top edge of the pan. Place the tart pan on a large rimmed baking sheet.
Combine 4 tablespoons sugar, almond flour, all-purpose flour, lemon zest, almond extract and salt in a small bowl; sprinkle in an even layer over the bottom of the prepared crust. Arrange the cooled plum pieces over the sugar mixture; dot with butter pieces. Sprinkle with the remaining 2 tablespoons sugar. Bake on the center rack until the filling is bubbly and the crust is golden brown, about 1 hour, covering with foil during the last 10 to 15 minutes to prevent overbrowning, if necessary.
Combine preserves and water in a small saucepan; bring to a simmer over medium heat. Brush the preserves mixture over the tart filling. Let the tart cool on a wire rack, about 45 minutes. Remove the pan sides; serve the tart warm or at room temperature.
Cover and refrigerate for up to 3 days.
11-inch tart pan with removable bottom