Line a 9x13 inch pan with aluminum foil hanging excess over the edges. Coat with nonstick cooking spray.
Take 1-1/2 cups of chocolate chips in a medium bowl and microwave on 3/4 power in 30 second increments, stirring after each, until the chocolate is completely melted and creamy smooth. Pour it into the bottom of the lined pan in an even layer.
Line up the pretzel sticks in neat rows so that you can cut your bars between the rows of pretzels. OR take a short cut and break the pretzels into pieces and scatter them in an even layer. Give them a gentle nudge, pushing them into the chocolate to set them. (making sure that the pretzels are pushed into the chocolate is key to being able to smoothly spread the next layer over them.) Place in the refrigerator while you work on the next layer.
In another bowl, whisk the peanut butter and melted butter together. Add the powdered sugar and continue to whisk until it is smooth. Carefully spread an even layer over the pretzels.
Now melt the rest of the chocolate (1-1/2 cups) in the same way that you melted the first batch. Pour it over the peanut butter layer and spread evenly. (This works best using an offset spatula)
Refrigerate the pan again until the bars are set. I have had the best results when waiting at least one hour before cutting it into bars.
Serve and enjoy this heavenly treat. Store any leftovers in an airtight container in the refrigerator.