Pistachio Shortbread

Directions

1. 1.

   Mix flour, powdered sugar, and salt in processor. Add butter, pistachios, egg yolk, and vanilla. Using on/off turns, mix until moist ball forms. Transfer dough to work surface. Divide dough in half. Form each dough half into 8 x 1 1/4-inch log (if dough is too soft, chill until firm, about 30 minutes). Wrap logs in plastic; refrigerate until firm, about 4 hours. DO AHEAD Can be made 5 days ahead; keep chilled.

2. 2.

   Preheat oven to 325°F. Slice logs into 1/4-inch-thick rounds, rolling log after every few slices to retain round shape. Place rounds on ungreased baking sheets, spacing 1 inch apart. Bake shortbread until barely golden, about 18 minutes. Cool shortbread on baking sheets. DO AHEAD Shortbread can be made up to 4 days ahead. Store shortbread in airtight container at room temperature.