Preheat oven to 350 degrees F. Line an 8x8" or 9x9" square baking pan with foil, extending the sides of the foil over the edges of the pan. Spray the foil liberally with cooking spray.
Unwrap one package of the refrigerated cookie dough (or cut the large log of dough in half). Press the dough evenly into the baking pan and bake for approx. 10 minutes. Remove the pan from the oven but keep the oven on.
Sprinkle the cookie layer with the chocolate chips, chopped Snickers bars, and chopped peanuts. Meanwhile, in a medium bowl, combine the caramel candies and the sweetened condensed milk. Microwave on HIGH power for about 30 seconds. Stir, then microwave again if needed for another 15-20 seconds, stirring until smooth.
Pour the caramel evenly over the bars. Top with the remaining cookie dough by either forming it into a square shape on a cutting board, picking it up and laying it on top of the bars, or by tearing off little pieces of dough, gently smooshing them in the palm of your hand, and laying them on top of the caramel almost like a puzzle.
Bake for approx. 25-30 minutes or until the top is golden and just about set. If it's sloshing around in the pan, bake it for another 5-10 minutes. It's okay if it's a little bit jiggly. Cool COMPLETELY, then pop in the fridge for about 1-2 hours or until it's sufficiently chilled before cutting into bars.