1/2 c. crunchy peanut butter
1/3 c. butter, softened
3/4 c. light brown sugar, packed
3/4 c. sugar
2 eggs
2 tsp. vanilla
1 c. unsifted flour
1 tsp. baking powder
1/4 tsp. salt
2 c. (12 oz. pkg.) semi-sweet chocolate chips

Cream peanut butter, butter and both sugars in large bowl until light and fluffy. Add eggs and vanilla; beat well. Combine flour, baking powder, and salt; blend into peanut butter mixture. Spread batter into greased 13 x 9 inch pan. Sprinkle chocolate chips evenly over top. Bake at 350 degrees for 5 minutes. Remove from oven. Use a spatula or knife to swirl chips through batter for a marbled effect. Return to oven and bake at 350 degrees for 25 to 30 minutes. Cool and cut into bars. Yield: about 4 dozen.