Place the cream cheese into the bowl of a stand mixer fitted with a paddle attachment. Whip the cream cheese until smooth, about 1-2 minutes on medium speed. Scrap down the sides thoroughly.
Add in the cocoa powder, 2 cups of heavy whipping cream, and the sweetened condensed milk. Beginning on low speed, mix the ingredients together. Be sure to start this process off on the slowest speed on the mixer. As the cocoa powder mixes in, gradually increase the speed of the mixer until you reach medium - high speed.
Periodically turn off the mixer and scrap down the sides thoroughly. Then gradually increase the speed.
You will need to mix the ingredients for 2-4 minutes until the mixture thickens up and reaches the consistency of whipped butter or cream cheese.
Place 18 sandwich cookies into a sealable bag. Break the cookies apart by hitting the bag, lightly, with a rolling pin. I recommend leaving large chunks of cookies present. You do not want crumbs.
Fold the broken cookies into the cream mixture.
Spread the mixture into the prepared pie crust. Gently smooth.
Take the remaining cookies and cut them in half across the center. Place the cookie halves, cut side down, along the edge of the pie. Cover and chill for at least 1 hour in the fridge.
I like to serve each slice with a dollop of whipped cream (I love using Tru Whip - found in the freezer section).