Preheat oven to 375 degrees.

Split Oreo cookies, remove and discard cream filling.

Place Oreos in a food processor or high powered blender and finely crush.

Melt butter in a medium bowl in the microwave, then add crushed Oreo cookies and sugar and mix until combined.

Dump into pie pan and firmly press flat and up all the sides.

Bake for 10-15 minutes or until crisp. Let cool while you make the pudding.

Add egg yolks and milk to a small bowl and whisk together.

In a medium-large saucepan add sugar, cornstarch and salt, stir together and then whisk in egg-milk mixture.

Place over medium heat and stir constantly until the mixture starts to bubble and thicken (about 8 minutes). Then decrease heat and let cook for one more minute.

Remove from heat and add chocolate, butter and vanilla extract. Whisk until smooth and then pour into Oreo pie crust.

Immediately cover pudding with plastic wrap. Let the plastic fall directly on the pudding, this will keep the pudding from forming a "skin" on top. Chill pie overnight or at least 8 hours.

Combine all ingredients in a stand mixer and use the whisk attachment to beat until stiff peaks form.

Generously top your chilled pie!