Preheat the oven to 350 degrees and prepare a 9x13 baking pan with a light coating of cooking spray. Set aside.
In a large bowl, combine cake mix, water, vegetable oil, and eggs. Mix until thoroughly combined.
Pour batter into the prepared baking pan and bake for 25 minutes or until a toothpick inserted in center comes out clean.
Allow the cake to cool, then using the handle of a wooden spoon poke holes over each inch of the cake. Set aside.
In a medium bowl, combine the pudding mix and milk. Whisk together until smooth.
Pour pudding over cake and spread evenly.
Refrigerate for one hour.
Spread the whipped topping over the pudding layer.
Top with crushed oreos and serve.