16tablespoonsunsalted butter at room temperature2 sticks
zest from 1 lemon
4ouncesgood-quality white chocolatecoarsely chopped
Preheat the oven to 350°F.
Line a large baking sheet with parchment paper.
Whisk together the flour, baking powder and salt in a medium bowl.
In a stand mixer, beat the sugar, butter, and lemon zest until fluffy. Beat in the eggs one at a time. Add the flour mixture in two additions to avoid a flour flurry, and beat just until blended. Add the pistachios, cranberries and white chocolate, mix until just blended.
Divide the dough in half and form 2 13-inch long and 3-inch wide logs on the prepared baking sheet, leaving space all the way around each log. Bake until light golden, about 40 minutes. Cool for 30 minutes.
Place a log on the cutting board. Using a sharp serrated knife, cut the log on a diagonal into ½ to ¾-inch-thick slices. Arrange the biscotti, cut side down, on the baking sheet. Repeat with second log.
Bake the biscotti until they are pale golden, 15 to 20 minutes. Transfer the biscotti to a rack and cool completely.
The biscotti can be made ahead. Store them in an airtight container up to 4 days, or wrap them in foil and freeze in resealable plastic bags up to 3 weeks.