1/4 cup smooth or chunky peanut butter (your choice)
Line an 8x8-inch or a 9x9-inch baking pan with foil or parchment paper. We used 2 pieces, so that they crossed, and all 4 walls of the pan were covered. This makes for easy removal from the pan.
In a microwave safe bowl, mix semi-sweet chocolate and sweetened condensed milk. Microwave on medium for 2 minutes, stirring after 1 minute. Stir until chocolate is completely melted. Stir in the peanuts. Spread into prepared pan. Place in refrigerator until the next layer is ready.
In another microwave safe bow, melt white chocolate on medium for 1 1/2 minutes or until the chocolate is almost melted, stirring after 1 minute. Stir until the chocolate is completely melted. Add the peanut butter, and stir until melted. Spread over the semi-sweet chocolate layer.
Refrigerate for 2 hours, or until firm. Cut into 1-inch squares and serve.