Preheat the oven to 350 degrees Fahrenheit. Prepare a baking sheet with parchment paper.
In a food processor or blender, add the oreos and pulse until finely crushed.
In a mixing bowl add the crushed oreos, cocoa powder, flour, cornstarch, baking soda, baking powder and salt. Whisk together these dry ingredients.
In a separate bowl, add the softened butter, sugars, egg and vanilla extract. Mix together until creamy.
Pour the dry ingredients into the wet ingredient bowl and fold everything together until a cookie dough forms.
Use a scooper to create large cookie dough balls and place on the parchment covered baking sheet about 2 inches apart from each other. Flatten slightly.
Bake in the oven for 10 minutes.
While the cookies are baking, make the whipped filling. Add the milk, heavy cream, pudding mix, powdered sugar, vanilla and melted chocolate in a bowl all at once.
Use a hand mixer to blend on low to medium speed until the chocolate mixture becomes a thick cream.
When the cookies are done baking, immediately use the bottom of a cup or measuring cup to flatten the center of each cookie. This creates a divot for the pie-like filling to sit in later. Let them cool for 15 minutes.
Once the cookies aren’t too hot anymore, scoop a large spoonful of the chocolate cream filling in the center of each cookie.
Top each with a squirt of whipped cream and enjoy!