Preheat oven to 350 degrees F.
Place the Oreos in a gallon-size resealable bag and smash with a rolling pin into fine crumbs (or pulse in a food processor for the same effect). Press the cookie mixture in an even layer along the bottom of the pan.
Place the peanut butter in a microwave-safe bowl. Microwave for 20 seconds, stir, and drizzle along the cookie mixture. Sprinkle the chocolate chips and pistachios on top.
Separate out 1/4 cup of sweetened condensed milk. Set aside. Take the remaining sweetened condensed milk and drizzle it atop the cookie-chip-nut mixture. Crumble the potato chips and add them on top, along with the coconut. Drizzle the remaining sweetened condensed milk on top to help all of the layers combine.
Bake until the coconut is lightly golden and the sweetened condensed milk is bubbly, about 22 to 25 minutes. Cool completely before cutting and serving.
