Prepare the Crust:

• In a large mixing bowl, combine the crushed Oreo cookies and melted butter. Stir until the mixture resembles wet sand.
• Press the mixture into the bottom of a greased 9×13-inch baking dish to form the crust. Place it in the refrigerator while you prepare the filling.

Prepare the Filling:

• In a separate bowl, beat the softened cream cheese and powdered sugar together until smooth and creamy. Add vanilla extract and mix well.
• In another bowl, whisk together the heavy cream and vanilla pudding mix until thickened, about 2 minutes.
• Gently fold the whipped cream mixture into the cream cheese mixture, combining until smooth.
• If desired, fold in the mini marshmallows for extra texture.

Assemble the Casserole:

• Spread the cream cheese mixture over the chilled Oreo crust.
• Top with additional crushed Oreos and mini marshmallows, if desired.

Make the Chocolate Drizzle:

• In a microwave-safe bowl, melt the chocolate chips and 1/4 cup heavy cream together in the microwave, stirring every 20 seconds until smooth and fully melted.
• Drizzle the chocolate over the casserole.

Chill and Serve:

• Refrigerate the casserole for at least 3 hours, or overnight, to let the flavors set and firm up.
• Slice into squares and serve chilled.