1/2 c. peanut butter
1/3 c. softened butter
3/4 c. firmly packed brown sugar
2 eggs
1 c. flour
1/4 tsp. salt
2 tsp. vanilla
1 tsp. baking powder
1 (6 oz.) pkg. chocolate chips

Beat first 4 ingredients until creamy. Add next 5 ingredients. Spread into greased 9 x 13 inch pan. Sprinkle with chocolate chips over surface. Place in 350 degree oven for 5 minutes, run knife through to marbleize. Bake 15-20 minutes more, cut into bars.