In a medium bowl, mix together the butter, graham cracker crumbs, confectioners' sugar, and creamy peanut butter until well blended.
Press the peanut butter mixture evenly into the bottom of an ungreased 9x13 inch pan, then place into the refrigerator to chill for 15 minutes.
While the pan is chilling, melt the chocolate chips with the peanut butter, stirring occasionally until smooth. I use a microwave safe bowl and heat it in 15-20 second intervals, stirring between.
Pour the chocolate mixture over the peanut butter bottom, spreading out gently to make an even layer.
Refrigerate until set, around one hour, then slice into squares.
Notes
These freeze exceptionally well, just place in a closed container and freeze up to 3 months ( as if they last that long)