1/2 c. peanut butter
1/3 c. butter, softened
3/4 c. brown sugar
3/4 c. sugar
2 eggs
2 tsp. vanilla
1 c. flour
1 tsp. baking powder
1/4 tsp. salt
2 c. semi-sweet chocolate chips

Combine peanut butter, butter, brown sugar, and sugar. Beat until creamy.

Gradually beat in vanilla. Combine flour, baking powder, and salt; blend into peanut butter mixture.

Spread into greased 9 x 13 pan. Sprinkle chocolate chips over surface. Place in 350 degree oven for 5 minutes. Remove from oven, run knife through to marbelize. Return to oven and bake 15-20 minutes. Do not over bake. Cut while warm.