This English pastry is noteworthy for its slick of jam topped with fragrant frangipane. Martha made this recipe on Martha Bakes episode 605.
Make the tart shells: In bowl of food processor, combine butter and granulated sugar and process until smooth. Add egg yolks, salt, and vanilla and process until combined, about 30 seconds. Add 1 cup flour and process until smooth. Add remaining 1 cup flour; process to combine. Turn dough out onto plastic wrap and form into a flat square; wrap tightly and refrigerate until chilled, about 1 hour. Wipe clean food processor bowl.
Make the filling: In bowl of food processor, add almonds and granulated sugar and process until finely ground. Add butter, egg, flour, rum, salt, and almond extract, and process until frangipane is smooth.
On a lightly floured work surface, roll out chilled dough to a 1/4-inch-thickness. Using a 4 1/2-inch round cutter, cut out 10 circles, re-rolling dough as necessary. Fit each circle into a 4-inch round fluted tart pan with removable bottom, and refrigerate until firm, about 1 hour.
Preheat oven to 350 degrees. Fill each tart shell with 1 tablespoon jam, then top with about 2 tablespoons frangipane; place on parchment paper-lined rimmed baking sheet. (You will have about 1/4 cup frangipane leftover.) Bake until golden, 30 to 35 minutes. Transfer to a wire rack to cool completely. Remove tarts from pans.
Make the glaze: Sift confectioners' sugar into a bowl. Stir in lemon juice to combine. Transfer to a pastry bag fitted with a small round tip. Pipe glaze onto tarts as desired.