Step 1: Preheat your oven
Preheat to 350°F (175°C). Grease your 9×13 baking dish lightly or use non-stick spray.

Step 2: Layer the Oreos
Place the Oreos in a single layer across the bottom of the dish. You can break them slightly or leave them whole—either works fine. Reserve a few to crumble on top after baking, if desired.

Step 3: Add the pudding layer
In a bowl, whisk together the milk and instant pudding mix until thickened (about 1–2 minutes). Pour the pudding evenly over the Oreos and spread gently to cover.

Step 4: Add the cake mix
Sprinkle the dry Devil’s Food cake mix evenly over the top of the pudding. Do not stir.

Step 5: Pour the butter
Drizzle the melted butter over the entire surface, trying to moisten as much of the cake mix as possible. Don’t worry if some dry spots remain—moisture from the pudding and butter will blend everything during baking.

Step 6: Bake
Bake uncovered for 40–45 minutes, or until the top is bubbly and set. The edges should be slightly crisp, and the center will be gooey.

Step 7: Cool and serve
Let the dump cake cool for at least 15–20 minutes before serving. It will thicken as it rests. Top with ice cream, whipped cream, or crushed Oreos for the ultimate finish.