Beat butter and shortening at medium speed with an electric mixer until creamy; add chunky peanut butter and sugars, beating well. Add eggs, beating until blended.

Combine flour and next 5 ingredients. Add to butter mixture, beating well.

Stir in peanuts and chocolate chunks.

Shape dough into 2-inch balls (about 2 tablespoons for each cookie). Flatten slightly, and place on ungreased baking sheets.

Bake at 375° for 12 to 15 minutes or until lightly browned. Cool on pan 1 to 2 minutes; remove to wire rack to cool completely.