8 T (1 stick) unsalted butter
¾ c sugar
2 large eggs
1 t pure vanilla extract
1 t freshly grated lemon or orange zest
2½ c all-purpose flour
1½ t baking powder
¼ t salt
1 c shelled pistachios
1 c dried apricots cut into ¼-inch dice
Heat oven to 350°. In the bowl of an electric mixer fitted with the paddle attachment, beat butter and sugar on medium-high speed until smooth, about 2 minutes. Add eggs, extract, and zest, and beat on medium speed until creamy and light, 2 to 3 minutes.
In a medium bowl, combine remaining ingredients. Add to butter mixture. Mix on low speed until just incorporated. Remove dough to a clean surface; divide into quarters. Form into 9-by-1-inch logs, place on an ungreased baking sheet 2 inches apart, and bake until lightly browned, 25 to 30 minutes.
Remove from oven, and cool slightly. Reduce oven temperature to 275°F. Using a serrated knife, cut logs on the diagonal into 1/2-inch thick slices. Arrange biscotti on their sides on a baking sheet. Return to oven, and bake until golden, about 30 minutes. Turn biscotti over, and bake for 30 minutes more.