To make the crust: Remove filling from all Oreo cookies. Place cookie shells in a food processor and blend until fine crumbs remain. Alternatively, if you do not have a food processor, a rolling pin and a heavy duty freezer ziplock back will do just fine! Seal bag with as much air removed as possible, and roll out until cookies are fine crumbs.  Melt butter in a small microwave safe bowl, about 30 seconds. Be careful as butter might be hot and you do not want any splatter to burn you. Combine cookie crumbs, butter, sugar, and vanilla in a bowl until a course sand-like mixture occurs. Press firmly into your tart pan with a removable bottom. These pans are highly non-stick so buttering or spraying ahead of time is generally not necessary. Use a measuring cup to ensure sides and bottom of tart crust is as firmly packed as possible. Bake at 350° for 12 to 15 minutes. Remove from oven and allow to cool completely. 

Make the filling: Mix cream cheese, peanut butter, sugar, and vanilla in a bowl until combined. Fold into whipped cream until completely incorporated. Pour into cooled tart shells, and refrigerate for 20 minutes.

Make the topping: Melt chocolate chips in a microwave save bowl for 60 seconds on high. Whisk until smooth and lump-free. Gently spread melted chocolate over peanut butter tart. Refrigerate for an additional one to two hours, or until set. Slice and serve cold. Store covered in the refrigerator for up to three days.