Preheat oven to 350 degrees F (175 degrees C ). Grease a 9x9 inch baking pan. In a medium bowl, cream together peanut butter and butter. Gradually blend in the sugars, eggs and vanilla; mix until fluffy. Combine flour, baking powder, and salt; stir into the peanut butter mixture until well blended. Stir in chocolate chips, if desired. Bake for 30-35 minutes in preheated oven, or until the top springs back when touched. Cool, and cut into squares. |