Preheat oven to 350°.
Stir together dry ingredients (first 3); set aside.
In large bowl combine brown sugar and oil till combined well; beat in eggs one at a time.
Add vanilla and blend well.
Add flour mixture, chips and nuts; mix completely.
Pour into prepared pan.
Bake at 350° for 35-40 minutes. Test with toothpick.
Careful not to over bake. Check at 35 minutes.
Cool on wire rack.
Cut into squares and when cool store airtight.