- 1/3 cup coarsely chopped pecans
- 1/4 cup sugar
- 1 1/4 cups all purpose flour
- 1/4 teaspoon salt
- 1/2 cup (1 stick) chilled unsalted butter, cut into 1/2-inch cubes
- 1/4 cup coarsely chopped pecans
- 2 tablespoons sugar
- 2 tablespoons (1/4 stick) unsalted butter, room temperature
- 1 large egg white
- 4 firm but ripe unpeeled nectarines, halved, pitted
- 1/3 cup apricot preserves
- 1 tablespoon water
- Finely chop pecans with sugar in processor. Add flour and salt; process 30 seconds to blend. Add butter; process just until clumps form. Gather dough together; flatten into rectangle. Wrap in plastic; chill 30 minutes.
- Line large rimmed baking sheet with parchment paper. Roll out dough on lightly floured work surface to generous 12×10-inch rectangle. Trim edges just to even sides. Cut dough into eight 5×3-inch rectangles. Transfer rectangles to prepared baking sheet, spacing 1 inch apart. Chill while preparing topping.
- Preheat oven to 375°F. Combine pecans, sugar, and butter in processor. Process until pecans are very finely chopped. Add egg white and process until well blended. Divide pecan topping equally among dough rect-angles; spread to within 1/4 inch of edges. Bake until pecan topping is set but cookies are still pale, about 10 minutes. Remove cookies from oven; maintain oven temperature.
- Thinly slice nectarine halves, keeping slices from each half together. Arrange 1 nectarine half atop each cookie, fanning slices decoratively. Return to oven and bake until cookies are light golden around edges, about 10 minutes. Transfer baking sheet with tarts to rack.
- Bring apricot preserves and 1 tablespoon water to simmer in heavy small saucepan. Strain glaze through sieve set over bowl. Brush glaze over nectarine slices. Cool tarts completely on baking sheet. (Tarts can be made 6 hours ahead. Let stand at room temperature. Rewarm any remaining glaze and brush over tarts before serving, if desired.)