Preheat the oven to 325 degrees F. Line a 9x13 inch pan with foil and spray with nonstick spray.
Place the Oreos (cream filling included!) in a food processor. Pulse the cookies until they become crumbs.
In a medium bowl, combine the crumbs and melted butter. Press the crumbs evenly into the prepared pan. Bake for 10 minutes. Remove to cool for at least 20 minutes before adding the filling. Keep the oven on.
CHEESECAKE
Place a large, rimmed baking sheet on the bottom rack of the oven and fill it halfway with water.
In a large bowl, use an electric mixer to beat the cream cheese until creamy. Then mix in the sugar, sour cream and vanilla; beat until smooth. Beat in the flour. Add the eggs one at a time, beating well after each addition. Stir in 1 cup of the mini chocolate chips.
Spread the cheesecake batter over the cooled crust. Sprinkle the top of the cheesecake with the remaining chocolate chips. Bake the cheesecake on a rack above the pan of water for 45 minutes.
Remove the pan from the oven and place it on a wire rack. Let the cheesecake cool for 1 hour, then refrigerate for 4 hours or until completely chilled.
Cut the cheesecake into 24 bars, and keep refrigerated until ready to serve.