Pulse the cookies in a food processor until finely ground.If you don't have a food processor, you can place them in a ziplock bag and crush them with a rolling pin.
In a medium bowl stir together oreo crumbs and melted butter.
Press oreo mixture into the bottom and up the sides of a lightly greased 9-inch pie pan.
In a large bowl, use hand-held mixer to beat the cream cheese until smooth.
Add the sweetened condensed milk and beat until blended.
Place chocolate chips in a microwave-safe bowl and heat microwave at 20 second intervals, stirring in between, until melted.
Add melted chocolate to cream cheese mixture and beat until blended.
Beat in the eggs and vanilla. Transfer filling to prepared pie crust.
Bake for 30 to 35 minutes.
Let cool completely before serving. I like to chill it and serve it cold with whipped cream.