Preheat the oven to 350-degrees. Prepare a 13x9-inch pan by coating with a light mist of cooking spray.
Combine the cookie mix, oil, water, and egg in a large mixing bowl, until well mixed. Press the dough into the pan and bake for 15-18 minutes until the edges are golden brown. Cool completely.
I'm in love with the ChocoMaker brand dark chocolate wafers. They melt beautifully and the taste is rich and chocolaty.
Add the wafers to a microwave safe bowl, and heat in 30-second intervals, stirring in between. Once the chocolate is smooth, spread it over the cookie bars. Sprinkle with the chopped peanut butter cups.
Refrigerate 30-minutes until set - this is the hardest part! Cut into bars (the chocolate may crack, but that's ok) and serve. Store leftovers in the refrigerator - if there are any!