Mix the crushed Oreo cookies with melted butter until well combined. Press the mixture into the bottom of a 9x13-inch dish, creating an even layer. Chill in the refrigerator while preparing the filling.

In a large mixing bowl, beat together the cream cheese and peanut butter until smooth.

Add powdered sugar and vanilla extract, and continue beating until well combined.

Gently fold in the whipped cream until the mixture is uniform. Spread the peanut butter filling over the chilled Oreo crust. Place back in the refrigerator to chill while preparing the ganache.

Heat the heavy cream in a small saucepan over medium heat just until it begins to simmer. Do not boil.

Pour the hot cream over the chocolate chips in a bowl. Let it sit for a minute, then stir until the chocolate is completely melted and the mixture is smooth.

Pour the ganache over the peanut butter layer, spreading it out evenly. Return to the refrigerator to chill for at least 1 hour, or until the ganache is set.

Spread whipped cream over the set ganache. Sprinkle with crushed Oreo cookies and chopped mini peanut butter cups, if using.

Chill the dessert for an additional 2-3 hours, or until set, before slicing and serving.