For the crust:
For the filling:
1. Preheat oven to 325F (165C).
2. In a food processor or Ziploc bag crush Oreo cookies to fine crumbs. Add melted butter and pulse until combined.
3. Press into 9X9-inch (22X22cm) square pan or 20X25cm rectangle pan baking lined with parchment paper. Bake for 10 minutes. Set aside while making the filling.
4. In a large bowl beat cream cheese, vanilla extract and sugar until smooth. Add sour cream, beat until smooth. Add eggs, one at the time, beating to combine after each addition.
5. Crush or chop Oreo cookies and fold into the filling. Pour the filing over the crust. And sprinkle some crushed Oreos (optional).
6. Bake for 40-45 minutes or until almost set. Let cool to room temperature, then refrigerate for at least 4 hours. Cut into squares