Begin by crushing about 24 chocolate sandwich cookies into fine crumbs using a food processor or a plastic bag with a rolling pin.

Combine the crushed cookies with 2-3 tablespoons of melted butter if desired, then press the mixture into the bottom of a 9x13 inch dish to form a crust.

In a large mixing bowl, beat 8 ounces of softened cream cheese until smooth. Gradually add powdered sugar and 8 ounces of whipped topping, mixing until blended and fluffy.

Spread the cream cheese mixture evenly over the cookie crust with a spatula.

Whisk together one package of instant vanilla pudding mix with 2 cups of cold milk for about 2 minutes until it thickens, then fold in another 8 ounces of whipped topping.

Spread this pudding mixture over the cream cheese layer, smoothing it out evenly.

Optionally, spread a layer of chocolate ganache or chocolate whipped topping over the pudding layer for extra richness.

Spread the remaining whipped topping over the entire dessert, then decorate with crushed peppermint candies and red and green M&Ms.

Cover and refrigerate for at least 4 hours or overnight to allow the layers to set.