• 1 1/4 cups unbleached all-purpose flour , plus more for dusting
• 2 Tbsp. sugar
• 1 tsp. salt
• 7 Tbsp. unsalted butter , cut into very small pieces and chilled

• 1/2 cup sugar
• 3 Tbsp. unbleached all-purpose flour
• 1 tsp. ground cinnamon
• 1 1/2 pounds plums (about 24 small prune plums or 12 small black plums)
• 2 Tbsp. unsalted butter , chilled and cut into small pieces
• Vanilla ice cream , for serving

1. To make crust: In a medium bowl, stir together flour, sugar, and salt until combined. Using a pastry blender, two knives, or your fingers, cut or rub butter into dry ingredients until mixture resembles a coarse meal. (Work quickly to keep the butter cold.) Using a fork, stir in 3 to 4 tablespoons cold water, 1 tablespoon at a time, adding just enough for the dough to hold together without becoming wet. Or combine flour, sugar, and salt in the bowl of a food processor. Add butter; process until mixture resembles a coarse meal. Drizzle in cold water; pulse just until dough begins to hold together. Turn dough out onto a clean surface. Gather into a ball and flatten into a 6-inch disk. Wrap in plastic wrap and chill 1 hour or up to 1 day.

2. Preheat oven to 425°. Roll out dough on a floured surface, making it 11 inches round. Fit into a 9 x 1 round tart pan with removable bottom, pressing snugly into corners of pan. Roll a rolling pin over top of pan to trim off excess dough. Cover with plastic and refrigerate or freeze 15 minutes.

3. Pierce bottom of shell all over with a fork. Line with foil and fill with pie weights or dry beans. Bake 10 minutes; remove foil and weights. Bake 5 minutes more, or until golden (if crust puffs up, press down with the back of a spoon). Place on a rack to cool.

4. To make filling: In a small bowl, whisk together sugar, flour, and cinnamon. Sprinkle ⅓ cup sugar mixture on pastry bottom. Slice plums; arrange in concentric circles on top. Sprinkle with remaining sugar mixture and dot with butter.

5. Bake 10 minutes. Reduce oven to 350° and bake until mixture begins to bubble around edges, 30 to 35 minutes. If crust begins to brown too quickly, cover with strips of foil. Cool on rack and serve warm with vanilla ice cream.