1. Preheat oven to 350°F.
2. Place all of the butter (1/2 cup plus 2 Tablespoons), brown sugar, eggs, and vanilla in a mixing bowl. Mix well.
3. Add flour, baking powder, and salt. Mix well.
4. Stir in nuts and chocolate chips.
5. Grease and flour an 9x13x2 inch baking pan.
6. Press dough into the pan.
7. Bake for 25-30 minutes.
8. Cool in pan before cutting.