Makes about 28 cookies
3 cups flour
2 teaspoons baking powder
In a large bowl, mix together the flour, baking powder, and salt in a large bowl. Add the chocolate chips and set aside.
In the bowl of an electric mixer fitted with the paddle attachment cream together the butter, peanut butter, sugar and vanilla. Add the eggs, one at a time, until they are well incorporated. Slowly add the dry ingredients to the wet, mixing until fully incorporated. Cover bowl with plastic wrap and chill in the fridge for 20 minutes.
While the dough is chilling preheat oven to 350 F.
Using your hands, shape chilled dough into 2 4 by 10 inch logs and place on an ungreased baking sheet. Bake until pale golden, 25-30 minutes.
Remove biscotti from the oven and transfer pan to a wire rack to cool for 20 minutes. Reduce oven temperature to 300 F.
Once cool, use a very sharp serated knife to cut the logs into slices about 3/4 inch thick. Place the slices cut side down on the cookie sheet and bake, turning once, until crisp, an additional 7-9 minutes on each side.
These cookies will stay fresh for 3 to 4 months if kept in an airtight container.