Prepare Oreo Crust using Peanut Butter Oreos (or regular Oreos) according to directions HERE. Place in the refrigerator or freezer to set, at least 30 minutes, more if using the baked version. *Note, you could also purchase a prepared crust.
To prepare the filling, beat the cream cheese, cold, for a full minute in a stand mixer on medium high. *Note, You could also use a hand-held mixer.
Add sugar and beat until sugar is melted and no longer grainy, about 2-3 minutes. Add cocoa, milk and vanilla. Beat until well combined and creamy. Stir in the whipped topping.
Meanwhile, place 8 Reese's peanut butter cups in a food processor and pulse until crumbled. Alternatively you could cut into very small chunks.
Fold about 2/3 of the crumbled Reese's Peanut Butter Cups into the chocolate mixture. Pour half of the mixture into the prepared Oreo crust, smoothing the top with the back of a metal spoon. Plunk about 7 Reese's Peanut Butter cups through the pie. Top with remaining mixture and gently smooth with the back of a metal spoon.
Sprinkle remaining Reese's crumbles on top for garnish, and place the remaining whole Peanut Butter cup on top of the pie.
Refrigerate for at least 3 hours before serving. This cheesecake is also delicious frozen. Just set out for 20 minutes before slicing.
Use any flavor of Oreos here that will compliment peanut butter.*Tip - wipe the knife with a wet paper towel before each slice.