1. Line an 8×8-inch baking dish with parchment paper, leaving some overhang for easy removal later.
2. Place the Oreo cookies in a food processor and pulse until finely crushed. If you don’t have a food processor, place the cookies in a sealed plastic bag and crush with a rolling pin until you have fine crumbs.
3. In a medium bowl, combine the melted butter and peanut butter, stirring until smooth and well blended.
4. Add the powdered sugar to the peanut butter mixture and stir until fully incorporated. This creates the creamy, sweet filling that helps hold the bars together.
5. Remove about 1/2 cup of the crushed Oreo crumbs and set aside for topping.
6. Press the remaining crushed Oreos firmly into the bottom of the prepared baking dish to form the base layer.
7. Spread the peanut butter mixture evenly over the Oreo base, smoothing it out with the back of a spoon or spatula.
8. Sprinkle the reserved Oreo crumbs evenly over the peanut butter layer.
9. In a microwave-safe bowl, combine the chocolate chips and coconut oil. Microwave in 30-second intervals, stirring in between, until the chocolate is fully melted and smooth.
10. Pour the melted chocolate over the top of the bars, spreading it evenly to cover the entire surface.
11. Refrigerate the bars for at least 2 hours, or until the chocolate is set and bars are firm.
12. Use the parchment paper overhang to lift the bars from the dish, then cut into 12 squares. Serve chilled for the best texture.

One tip I’ve learned from years of family cooking is to be gentle when pressing the Oreo base—too much pressure and the layer can become too dense, which affects the lightness of the bars. Also, letting the bars chill overnight makes for cleaner cuts and a more satisfying snap when you bite in.