Ground almonds add a delicate nutty flavor to the crust. Begin making the filling a day before assembling the tart; once completed, it can be chilled another day before serving.
02Lightly butter 9-inch-diameter tart pan with removable bottom. Blend flour, 1/4 cup sliced almonds, sugar, and salt in processor until almonds are finely ground. Add butter; using on/off turns, cut in until mixture resembles coarse meal. Whisk egg yolk and almond extract in small bowl; add to processor and blend until moist clumps form. Gather dough into ball; flatten into disk. Press dough onto bottom and up sides of prepared pan. Pierce crust all over with fork; freeze 30 minutes.
03Preheat oven to 375°F. Line crust with foil; fill with dried beans or pie weights. Bake until crust is set, about 12 minutes. Remove foil and beans. Bake until crust is golden, about 18 minutes longer. Cool crust completely on rack.
04Spread filling in crust; sprinkle remaining 2 baskets berries over. Stir currant jelly in small saucepan over medium heat until melted; brush over berries. Sprinkle remaining 2 tablespoons sliced almonds around edge of tart. Cover loosely with foil and chill at least 2 hours. (Can be made 1 day ahead. Keep refrigerated.)
05Remove pan sides. Place tart on platter. Serve cold or at room temperature.