3 cups all-purpose flour
2 tsp. baking powder
½ tsp. salt
6 tbsp. unsalted butter, at room temperature
¾ cup creamy peanut butter
1 cup sugar
2 tsp. vanilla extract
3 large eggs
1 cup mini chocolate chips (or chopped dark chocolate)
Additional chocolate, for drizzling (optional)
Preheat the oven to 350˚ F. Line a baking sheet with parchment paper or a silicone baking mat. In a medium bowl, combine the flour, baking powder and salt. Whisk to blend. In the bowl of an electric mixer, combine the butter, peanut butter and sugar. Beat on medium-high speed until fluffy and smooth, 1-2 minutes. Blend in the vanilla. Beat in the eggs one at a time, scraping down the bowl as needed between additions. With the mixer on low speed, blend in the dry ingredients just until incorporated. Stir in the chocolate chips or chocolate chunks until evenly distributed.
Divide the dough in half. Shape into logs on the prepared baking sheet, about 11- by 3-inches in size, spacing at least 3 inches apart. Bake for 30 minutes. Remove the pan from the oven while maintaining the oven temperature. Let the logs cool for 10 minutes. Slice the logs diagonally into slices about ½- to ¾-inch thick. Lay the slices, cut side down, on the baking sheet. Bake, turning once, until the slices are slightly crisp, about 20-30 minutes more. Transfer to a cooling rack and let cool completely. If desired, drizzle cooled biscotti with additional melted chocolate. Let set before serving.