Preheat oven to 325 degrees F. In a food processor, combine flour, brown sugar, ginger, lemon zest, and salt. Mix until blended well. Add butter and process until the mixture resembles coarse meal. Take care not to over process.
Pat dough evenly over the bottom of an ungreased 9-inch springform pan. Press a fork on edges all around to make a decorative border. Prick the dough every 2 to 3 inches with the fork.
Bake for about 1 hour, or until lightly browned and firm in the center. Remove pan sides and score into serving size wedges while still warm. If desired, dust shortbread with confectioners' sugar.
Let cool to room temperature before serving. Store for up to 5 days in an airtight container, or freeze for several months.
Makes about a dozen wedges.
Date: November 2, 2002