Step 1 In a medium bowl, stir together the flour, baking powder, baking soda and salt in a medium bowl and set aside.
Step 2 Beat the butter until creamy in a stand mixer or in a medium bowl using a hand mixer. Beat in the peanut butter until blended. Beat in the sugar and brown sugar until light and fluffy.
Step 3Beat the egg and vanilla into the sugar mixture until blended. Add flour mixture and beat until thoroughly mixed. Then stir in the chopped peanuts and chocolate until evenly incorporated.
Step 4Divide the dough in half. Shape it into two logs about 9 inches long and wrap each log in plastic wrap, waxed paper or aluminum foil. Twist ends to seal. Chill in the refrigerator overnight.
Step 5Heat the oven to 350 degrees. Unwrap the logs and cut into one-fourth-inch-thick slices. Place the slices on silicone-lined baking sheets, and bake 10 to 13 minutes until lightly browned around the edges. Remove the cookies to a wire rack to cool. Store the cookies in an airtight container.