1. Crush the chocolate sandwich cookies into fine crumbs and mix them with the melted butter until evenly combined. Press the mixture firmly into the bottom of a 9×13-inch dish and chill for 10 to 15 minutes.

2. In a medium bowl, beat the softened cream cheese until smooth. Add the powdered sugar and mix until creamy, then fold in 1 1/2 cups of the whipped topping until light and fluffy.

3. Spread the cream cheese mixture evenly over the chilled cookie crust, taking care to reach the edges.

4. In another bowl, whisk together the instant chocolate pudding mix, hot chocolate mix, and cold milk for about 2 minutes until smooth and thickened.

5. Spread the pudding mixture evenly over the cream cheese layer.

6. Top with the remaining whipped topping and smooth it into an even layer.

7. Sprinkle the mini marshmallows over the top, then finish with chocolate chips or chocolate shavings.

8. Cover and refrigerate for at least 4 hours, or overnight, before slicing and serving.