Vinegar Pie

Roll out half of pastry dough (reserve remainder for another use) on a lightly floured surface with a floured rolling pin into a 12-inch round. Fit dough into tart pan and trim excess, leaving a 1/2-inch overhang. Fold overhang inward and press against side of pan to form a rim that extends 1/4 inch above pan. Prick bottom of shell all over with a fork and chill 15 minutes.

Preheat oven to 400°F.

Line shell with foil and fill with pie weights.

Bake in middle of oven until edge is pale golden and sides are set, about 20 minutes.

Remove weights and foil and bake shell until bottom is golden, 8 to 10 minutes more.

Whisk together eggs and 1/4 cup sugar in a bowl until blended well.

Whisk together flour and remaining 3/4 cup sugar in a 1-quart heavy saucepan, then whisk in water and vinegar. Bring to a boil, whisking until sugar is dissolved.

Add to egg mixture in a slow stream, whisking constantly.

Pour filling into saucepan and cook over moderate heat, stirring constantly with a wooden spoon, until filling coats back of spoon and registers 175°F on an instant-read thermometer, 12 to 15 minutes. (Do not boil.) Immediately pour filling into a 2-cup glass measure. If pie shell is not ready, cover surface of filling with a round of wax paper.

Reduce oven temperature to 350°F, then pour hot filling into baked pie shell in middle of oven and cover rim of crust with a pie shield or foil (to prevent overbrowning).

Bake pie until filling is set, 15 to 20 minutes, then cool completely in pan on a rack. Dust evenly with cinnamon.