2 large eggs, plus 1 large egg white
2 cups all-purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
4 tablespoons unsalted butter, at room temperature
3/4 cup granulated sugar
1 teaspoon almond extract
1/2 teaspoon pure vanilla extract
1/2 cup unsalted, roasted pistachio nuts, coarsely chopped
1/2 cup packed dried apricots, coarsely chopped
1/4 cup sanding sugar or granulated sugar for sprinkling
Preheat the oven to 350°F (180°C). Line a baking sheet with parchment paper. In a small bowl, whisk the egg white with 1 teaspoon water; set aside.
In a bowl, whisk together flour, baking powder, and salt. In large bowl, using electric mixer on medium-high speed, beat butter and granulated sugar until fluffy, 2 minutes. Add 2 eggs and almond/vanilla extracts. Beat on low until eggs are incorporated.
Beating on low speed, slowly add the flour mixture and continue to beat until almost fully incorporated, scraping down the sides of the bowl as needed. Add the pistachios and apricots and beat on low speed just until distributed.
Divide the dough in half. Shape each piece into a 91⁄2-by-11⁄2-inch (24-by-4-cm) square log and transfer the logs to the prepared baking sheet, spacing them 4 inches (10 cm) apart. Brush the logs with the egg white mixture and sprinkle with sanding sugar
Bake until the edges of the biscotti are light brown and the tops feel firm, 20 - 24 minutes. Remove the cookies and leave the oven on. Transfer the sheet to a wire rack and let cool slightly, about 20 minutes
Using serrated knife, cut each log into 22 slices about 1⁄2 inch thick. Arrange slices, cut side down, on sheet and bake until the biscotti are golden brown, completely dry, 10-12 minutes. Using a metal spatula, transfer the biscott to wire rack, let cool
Store the cookies in an airtight container, layered between sheets of parchment paper, in the refrigerator for up to 1 week.