Screw peanut butter. Add reese's peanut butter chips into the chocolate chip cookie layer. I did and it was amazing.
Or once you lay down your cookie dough layer, swirl in bits of peanut butter, like you would fudge in brownie batter.
Or you can melt them (1 bag chips in microwave safe bowl, melt on high in 30 second intervals, stirring between nukings) and dump on, let set, then dump the caramel layer on.