Preheat oven to 400F. Line baking sheet with foil; butter foil. Place plums on prepared sheet, spacing evenly. Sprinkle with 2 tablespoons sugar. Bake until plums are tender but stil hold shape, about 30 minutes. Cool plums on sheet.
Roll out dough on floured surface to 12-inch-diameter round. Transfer pastry to center of another heavy large baking sheet. Overlap plums in concentric circles on pastry, forming 9-inch-diameter circle in center. Combine remaining 2 tablespoons sugar and cinnamon in small bowl. Sprinkle sugar mixture over plums. Fold edge of pastry over plums, pinching to seal any cracks in pastry. Brush crust twice with egg white.
Bake tart until crust is golden, about 25 minutes. Run thin sharp knife carefully under tart edges to loosen from sheet. Cool 15 to 30 minutes. Serve tart slightly warm with ice cream.
Bon Appetit/May 94 Typed by Didi Pahl