2/3 c. butter (or shortening)
1 lb. box brown sugar
3 eggs
1 tsp. vanilla
2 1/2 c. flour
2 1/2 tsp. baking powder
1/2 tsp. salt
1 pkg. chocolate chips, chopped (nuts are optional)

Preheat oven to 350 degrees. Grease 13 x 9 inch pan. Melt butter in saucepan. Cool; add brown sugar, mix well. Add eggs and vanilla. Blend in flour, baking powder and salt. Add chocolate chips and nuts (if desired). Pour into pan. Bake for 30-35 minutes or until top is light brown.