Prepare the brownies according the the directions for whatever brownies you choose to make.  About 5 minutes before they are done cooking, sprinkle the top with the chopped peanuts and peanut butter cups.  Finish baking the brownies for the remaining 5 minutes then remove from the oven.

Melt in a large glass bowl the milk chocolate chips, peanut butter and butter.  Microwave on high for 45 seconds and stir well.  Microwave another 30 seconds and stir well.  The heat of the mixture should finish melting the remaining chocolate.  Stir in the rice crispies then pour the mixture over the top of your brownies.  Spread to cover evenly.  Allow to cool, then refrigerate for at least 2 hours to let the topping firm up.  When cutting, wipe your knife after every pass to help make clean cuts.