Make the dough Place flour, powdered sugar, and salt in bowl of a food processor, and pulse twice to combine. Add butter, and pulse until butter is a mixture of pea-sized and smaller pieces. Whisk together egg yolk and water in a small bowl; slowly add to processor bowl through food chute, pulsing until just combined, about 34 pulses. (Mixture will not come together in 1 mass. Stop pulsing when dough is crumbly but holds together when squeezed.)

Evenly press dough on bottom and up sides of a 9-inch fluted round tart pan with a removable bottom. Prick dough using a fork; chill in freezer for at least 30 minutes or up to 12 hours. (Cover chilled dough once firm if freezing overnight.)

When ready to bake, preheat oven to 375°F. Remove tart pan from freezer; lightly grease 1 side of a sheet of aluminum foil with butter. Carefully line tart pan using aluminum foil, butter side down touching dough, and fill with pie weights; place tart pan on a rimmed baking sheet.

Bake the dough for 20 minutes; remove from oven, and remove foil and pie weights. Continue baking the crust until golden brown, 10 to 20 minutes. (If crust bubbles up while baking, carefully redock and deflate using a fork.) Let crust cool in tart pan on a wire rack until room temperature, 45 minutes to 1 hour. Meanwhile, reduce oven temperature to 350°F.

Make the filling Place almond flour, granulated sugar, all-purpose flour, and salt in bowl of food processor (no need to clean it first); pulse until combined, about 4 pulses. Add butter, almond extract, and egg; pulse until just combined, about 6 pulses, stopping to scrape down sides of bowl as needed.

To assemble, evenly spread jam over bottom of cooled crust placed on same rimmed baking sheet; spoon almond flour mixture evenly over top and spread into an even layer. Sprinkle with almonds (if using).

Bake the tart until the filling is puffed and golden brown, and a cake tester inserted into center of tart comes out clean, about 40 minutes, rotating tart pan 180 degrees halfway through baking time and tenting using aluminum foil if edges of crust are overbrowning.

Let cool in tart pan on a wire rack until room temperature, 1 hour, 30 minutes to 2 hours. Remove tart from pan, and transfer to a platter. Dust with powdered sugar before serving.