For the filling:

⅔ cup ground almonds

¼ cup granulated sugar

2 tablespoons butter, softened

1 egg, room temperature

¼ teaspoon almond extract

2 tablespoons unbleached all-purpose flour

1 pound prune plums

3 tablespoons apricot jam, melted and strained

For the tart shell:

1½ cups unbleached all-purpose flour

2 tablespoons granulated sugar

4 teaspoons cornstarch

¾ cup cold butter, cubed

Cook Mode Prevent your screen from going dark

In a large bowl, whisk together flour, sugar, and cornstarch. Cut in butter using a pastry blender or fingertips until the mixture starts to come together.
Press the dough evenly into the bottom and up the sides of a 9-inch tart pan with a removable bottom. Cover and refrigerate for 1 hour (or up to 3 days ahead).
Prick the bottom of the chilled crust with a fork and bake at 350°F (175°C) for 15 minutes, until lightly golden. Let cool completely on a wire rack.
For the filling, beat together ground almonds, sugar, and butter until smooth. Add egg and almond extract, then stir in flour until well combined.
Spread the almond filling evenly over the cooled tart shell.
Halve, pit, and thinly slice the plums. Arrange slices in concentric circles over the filling, cut-side down.
Bake for about 30 minutes, until the filling is firm to the touch and a tester inserted in the center comes out clean.
Cool the tart for 15 minutes, then brush the top with melted apricot jam for a glossy finish.
Remove the tart from the pan and let it cool completely before serving.

Use apricots, pears, or figs instead of plums for a seasonal variation.

Sprinkle sliced almonds on top before baking for extra crunch.

Gluten-free option: substitute almond flour and gluten-free pastry mix.

The apricot glaze adds shine and sweetness but can be omitted if desired.

Serve slightly cool or at room temperature for the best texture.