Using a food processor or a tightly sealed bag and mallet, crush chips and pour into a large mixing bowl.
Mix ¾ cup peanut butter, powdered sugar and butter into the crushed chips. Pour into 9x9" pan. I line mine with parchment paper, but they come out easily, even when ungreased.
Combine chocolate chips and remaining ¼ cup peanut butter. Microwave in 15 second intervals until smooth. Pour over the chip mixture, using a spatula to smooth.
Refrigerate at least two hours and serve chilled.
Video
Notes
You can cut butter down to 8 Tbsp if you wish.Store in an airtight container for up to 1 week.