Makes about 4 dozen.
These biscotti are crisp and delicious with a touch of lemon. They keep very well refrigerated in an air-tight container with wax paper between the layers. It's nice and convenient to have them on hand.
8 ounces shelled pistachios
1½ cups unbleached all-purpose flour
Scant 1 cup sugar
1 teaspoon baking powder
Grated zest of 1 lemon
2 large eggs plus 1 large egg yolk at room temperature, lightly beaten with a fork
1 teaspoon vanilla extract
¼ cup vegetable oil
Preheat the oven to 325F.
Spread pistachios on a baking sheet and bake until they are fragrant and just beginning to brown, 8-10 minutes. Cool.
Line an 18x13 inch cookie sheet with parchment paper.
Chop the pistachios coarsely, in 3 batches, in a food processor fitted with a steel blade and transfer to a large bowl.
Add the flour, sugar, baking powder and lemon zest.
Make a well in the center of the bowl and add the eggs, vanilla extract and oil. Mix well with a wooden spoon until dough sticks together. Transfer the dough to a lightly floured work surface and work with your hands to form a smooth rectangle, about 6x4.
Cut dough into 3 equal parts.
On a lightly floured work surface roll each piece of dough into a 12x1 inch smooth log. Lightly flatten the tops and square the ends. Place the logs on the cookie sheet, leaving a little space between them (they grow a bit).
Bake for 25 minutes, until the tops are firm to the touch.
Remove from the oven and transfer to a cutting board. While the logs are still warm, cut them with a serrated bread knife into ½ inch slices (do not be discouraged if some brake, it is the hard nuts that make it difficult to cut).
Arrange the biscotti on the same baking sheet and return them to the oven for 10 minutes, turn over and bake for another 10 minutes.
Cool on a wire rack.