Yummy!!
Combine flour, cocoa, baking powder,and salt in a small bowl.
Beat sugar, butter, eggs and vanilla in a large mixer bowl until creamy.
Add flour mixture; beat until smooth.
Stir in nuts and peanut butter chips.
Spread into a greased 9x13 inch baking pan.
Bake in preheated 350-degree oven for 20-25 minutes or until a wooden pick inserted near center comes out still SLIGHTLY STICKY.
Immediately sprinkle with chocolate chips; let stand for 5 minutes. Spread over brownines.
Cool in pan on wire rack.