Preheat your oven to 350°F (175°C). Prepare the chocolate cake mix according to the instructions on the box. Pour the batter into a greased 9x13 inch baking dish. Bake for about 25-30 minutes or until a toothpick inserted in the center comes out clean. Allow the cake to cool for 10 minutes before moving to the next step.

Once the cake has cooled slightly, poke holes evenly throughout the surface with a wooden spoon handle or skewer, about 20-30 holes.

Warm the hot fudge in the microwave for about 30 seconds, then pour it over the poked cake, focusing on getting it into the holes.

Let the cake cool completely at room temperature for about 30 minutes to set the fudge layer.

In a medium bowl, whisk together the chocolate instant pudding mix with 1¾ cups of cold milk until smooth. Let it sit for about 2 minutes to thicken, then pour it over the cooled cake.

Refrigerate the cake for approximately 20 minutes to allow the pudding to set.

Prepare the second pudding layer by mixing the remaining pudding with 1¾ cups of milk and allowing it to thicken. Fold in the Cool Whip until smooth, and mix in about ¾ of the crushed Oreos.

Spread the pudding and Cool Whip mixture over the cake, then sprinkle the remaining crushed Oreos on top. Serve immediately or chill until ready to enjoy.