Preheat oven to 350 degrees. Line a regular size muffin pan with paper liners or spray with nonstick cooking spray.
For the Chocolate Cake: In an electric mixer, beat together the cake and pudding mixes, sour cream, oil, beaten eggs, water and vanilla until well combined and smooth. Set aside.
For the Vanilla Cheesecake: In an electric mixer beat the cream cheese until fluffy. Add the sugar and vanilla, beating well. Beat in the egg and set aside.
For the Buttercream Dream Frosting: In an electric mixer, cream the butter and shortening until fluffy, about three minutes. Add the salt and vanilla and combine well. Begin adding the sugar, one cup at a time and mix thoroughly after each addition. After all the sugar has been added and mixed thoroughly, begin adding the very cold heavy whipping cream one tablespoon at a time, combining well after each addition. Beat on medium-high speed for three minutes to reach desired consistency.
To assemble: Use a scant tablespoon full of chocolate cake mix and smooth into the bottom of the muffin tin (I actually used my (very clean) finger to do this). Spoon in just enough cheesecake to cover the chocolate cake. Press an Oreo into the cheesecake and cover the Oreo with cheesecake mixture–just enough to cover the cookie. Top with another tablespoon of chocolate cake and gently spread until even in the tin. (Be careful to do no more than a tablespoon each time otherwise your muffin tin will be too full and the cupcake batter will rise above the muffin tin and “mushroom”) Repeat with remaining muffin tins. Bake for 18-22 minutes, or until top is springy to the touch. Place on wire rack and cool completely. Pipe frosting onto cooled cupcakes and store in an air-tight container in the refrigerator.
Recipe by DessertedPlanet.com at https://dessertedplanet.com/oreo-cheesecake-cupcakes/