Ingredients

• 1 1/4 cups all-purpose flour
• 1/4 teaspoon salt
• 3/4 stick cold unsalted butter, cut into 1/2-inch cubes
• 2 tablespoons cold vegetable shortening (preferably trans-fat-free)
• 3 to 4 tablespoons ice water
• 2/3 pound small firm-ripe prune plums (9 or 10), quartered lengthwise and pitted
• 1/3 cup plus 2 tablespoons sugar, divided
• 1/2 cup whole almonds with skinsv
• 1/4 cup all-purpose flour
• 1/8 teaspoon salt
• 1/2 stick unsalted butter, softened
• 1 large egg
• 1 tablespoon Amaretto (optional)
• Confectioners sugar for dusting
• Equipment:6 (4- by 3/4-inch) round nonstick tartlet pans

Instructions

1. Blend together flour, salt, butter, and shortening with your fingertips or a pastry blender (or pulse in a food processor) just until most of mixture resembles coarse meal with some small (roughly pea-size) butter lumps. Drizzle with 3 tablespoons ice water and gently stir with a fork until incorporated. Squeeze a small handful: If it doesn't hold together, add more ice water, 1/2 tablespoon at a time, stirring (or pulsing) until just incorporated, then test again. (Do not overwork, or pastry will be tough.)
2. Turn out mixture onto a lightly floured surface and divide into 4 portions. With heel of your hand, smear each portion once or twice in a forward motion. Gather dough together, with a pastry scraper if you have one, and press into a ball, then flatten into a 6-inch disk. Chill, wrapped in plastic wrap, until firm, at least 1 hour.
3. Macerate plums while dough chills: Toss plums with 2 tablespoons sugar in a bowl and let stand at room temperature 1 hour.
4. Toss plums with 2 tablespoons sugar in a bowl and let stand at room temperature 1 hour.
5. Prepare filling and make tartlets: Pulse almonds with flour, salt, and remaining 1/3 cup sugar in a food processor until very finely chopped, then add butter, egg, and Amaretto (if using), pulsing until just blended. Roll out dough into a 15-inch round (about 1/8 inch thick) on a floured surface with a floured rolling pin. Cut out 6 (5-inch) rounds and fit each round into a tartlet pan (don't trim). Prick bottoms all over with a fork and chill shells until firm, about 15 minutes. Preheat oven to 375°F with rack in middle. Drain plums, discarding juices. Divide almond filling among tartlet shells and arrange plums over it. Put pans on a baking sheet and bake until crust and filling are golden and plums are tender, 35 to 45 minutes. Cool tartlets completely in pans on a rack before unmolding. Just before serving, dust with confectioners sugar.
6. Pulse almonds with flour, salt, and remaining 1/3 cup sugar in a food processor until very finely chopped, then add butter, egg, and Amaretto (if using), pulsing until just blended.
7. Roll out dough into a 15-inch round (about 1/8 inch thick) on a floured surface with a floured rolling pin. Cut out 6 (5-inch) rounds and fit each round into a tartlet pan (don't trim). Prick bottoms all over with a fork and chill shells until firm, about 15 minutes.
8. Preheat oven to 375°F with rack in middle.
9. Drain plums, discarding juices. Divide almond filling among tartlet shells and arrange plums over it. Put pans on a baking sheet and bake until crust and filling are golden and plums are tender, 35 to 45 minutes. Cool tartlets completely in pans on a rack before unmolding. Just before serving, dust with confectioners sugar.