In a saucepan over low heat, whisk together the unsalted butter, sugar, and chopped dark chocolate until melted. Stir in the whole milk and vanilla extract, continuing to whisk until thickened. Let cool completely.

In a food processor, pulverize chocolate sandwich cookies into fine crumbs. Mix with melted butter until it resembles fine sand.

Press the cookie mixture into the bottom of a 13x17 cm mold, then chill in the fridge for 30 minutes.

In a mixing bowl, whip the fresh cream until stiff peaks form. Reserve 110g for later.

In another bowl, combine softened cream cheese, powdered sugar, and vanilla extract. Fold in the remaining whipped cream until smooth.

Spread the mousse evenly over the chilled cookie base and freeze for about 10 minutes.

Pour the cooled pudding over the mousse and smooth the top.

Spread the reserved whipped cream on top and optionally sprinkle with chocolate chips.

Slice and serve immediately, or chill in the fridge until ready to serve.