Modified from Gourmet May 1997.
The secret to this recipe is to freeze the dough before forming it into logs.
3 cups flour
4 teaspoons baking powder
1 cup sugar
7 tablespoons unsalted butter or margarine, room temperature
3 large eggs
3/4 cup chopped pecans (about 3 1/2 ounces)
1/2 cup finely chopped candied orange peel
3 tablespoons orange liqueur
1 large egg yolk, beaten to blend
Preheat oven to 350. Line 3 baking sheets with parchment paper. Lightly flour the waxed paper. Sift flour and baking powder into a bowl. In a bowl combine the sugar and butter. Mix well and add the eggs, beating until fluffy. Add the nuts and orange peel. Add flour mixture and liqueur and then beat until well blended.
Spoon dough out onto 1 prepared baking sheet, pressing to form 12-inch-long rectangle, about 5 inches wide (dough will be very soft). Place in freezer until firm, about 30 minutes.
Cut chilled dough lengthwise into 3 strips. Shape each strip on lightly floured surface into 12-inch-long, 1 1/2-inch-wide and 1-inch-high log. Transfer logs to remaining 2 prepared sheets, 1 log on 1 sheet and 2 logs on second sheet, spacing 2 inches apart. Brush logs with egg yolk. Bake until golden and firm to touch (dough will spread), about 30 minutes. Cool completely on baking sheets. Reduce oven temperature to 325. Using serrated knife, cut logs into 3/4-inch-wide diagonal slices. Stand biscotti slices upright on 2 heavy large baking sheets. Bake until biscotti are pale golden, about 25 minutes. Transfer to racks and cool. (These should be stored in airtight container.)