Make crust: Preheat oven to 425°F. Crumble 25 cookies into food processor; process until finally ground. Add melted butter, process until blended. Pour into 9-inch springform pan; Press over bottom and 3 inches up sides. Refrigerate until firm.

Meanwhile, make the filling: in large bowl of electric mixer, at medium high speed, beat cream cheese, butter and flour one minute or until blended and smooth. Beat in eggs, one at a time, beat in heavy cream and vanilla.

Crumble remaining cookies into food processor; Pulse until coarsely chopped. Remove; finally grind and reserve some for garnish. Pour half of the cheesecake batter over crust in prepared pan; sprinkle top with remaining batter. Place springform pan on a jelly roll pan; bake for 15 minutes. Reduce heat to 225°F; Bake 50 to 55 minutes, until firm around sides but still jiggly in center.

Make topping: In small bowl, combine sour cream, sugar and vanilla; mix well. Spread over top of cheesecake. Increase oven temperature to 350°F. Bake cheesecake 7 to 10 minutes. Place it on cooling rack. Cool to room temperature. Refrigerate several hours or overnight period sprinkle with reserved Oreos before serving.