Preheat oven to 350. Line 9x13 pan with foil so that small amount of the foil hangs over the edge. Spray foil with non-stick spray.
Combine butter, sugar, vanilla and eggs. Add flour, cocoa powder and baking powder. Pour into prepared pan and bake for about 20 - 25 minutes.
While brownies are baking, chop peanut butter cups and peanuts.
After brownies have baked for 20-25 minutes, top with the chopped peanut butter cups and the chopped peanuts. Return to oven and finish baking for 6 - 10 minutes, until wooden pick can be insterted and comes out clean.
While the brownies are finishing, make topping. In microwave safe bowl, put chocolate chips, butter and peanut butter and cook until melted, about 45 seconds. Stir well until mixture is smooth. Add the rice crispy cereal, stir to coat evenly.
When brownies are done, remove from oven and top with chocolate covered rice crispy cereal, spreading evenly over the top. Set aside and let cool for about a hour. Then move to refrigerator and chill for at least 2 hours.
To remove, lift out of pan by pulling up on the foil. Pull foil back from sides of brownies and cut into bars. Enjoy!