In a 2-gallon ziploc bag, add the graham crackers; close the zip-loc bag.
With a rolling pin, crush graham crackers into crumbs.
Add the graham cracker crumbs to a large bowl.
Also add the confectioners' sugar, and melted butter; mix well together.
Then add the creamy peanut butter; mixing all the ingredients together well.
Place the crumb mixture into one 15.25 x 10.25 x .75-inch jelly roll pan.
Pat crumb mixture down firmly into pan.
In a double boiler, (over low heat) melt together the chocolate chips, and the can of sweetened condensed milk; stirring often. This should take about 5 minutes.
After chocolate chips and condensed milk has melted together, quickly spread the chocolate mixture over the peanut butter mixture.
Chill the cookie-bars in the refrigerator for 4 hours.