Pulse together the flour, brown sugar, salt, baking powder, and baking soda in the work bowl of a food processor fitted with a steel blade. Add the pecans and ginger and pulse a few times.
Use a fork to lightly beat together the egg and vanilla in a small bowl. With the food processor running, pour this mixture through the feed tube and process until the dough forms itself into a ball, about 30 seconds.
Divide the dough into 4 equal pieces and form each into a log about 4 inches long, 1 1/2-inches wide, and 5/8-inch high. Place the logs on the baking sheet, leaving a few inches of space between them.
Bake the biscotti for 15 to 18 minutes, until they are light golden. Remove the baking sheet from the oven and cool on a rack for 10 minutes. Transfer the logs to a cutting board.
Using a serrated knife, cut each log on the diagonal into 1/2-inch-thick slices. Place the biscotti cut side down on the baking sheet.
Bake the biscotti another 8 to 10 minutes, until firm and set. Remove the baking sheet from the oven and cool the biscotti completely on the baking sheet on a rack.
Store the biscotti between layers of waxed paper in an airtight plastic container at room temperature up to 1 week. To freeze up to 4 months, wrap the container tightly in several layers of plastic wrap and aluminum foil. Use a large piece of masking tape and an indelible marker to label and date the contents. If frozen, defrost the biscotti overnight in the refrigerator and bring to room temperature before serving.
From Bite-Size Desserts by Carole Bloom. Copyright 2009 John Wiley & Sons.