Philadelphia OREO Cheesecake

1 pkg (550 g) OREO Cookies
1/4 cup melted butter
4 pkg (250 g each) Cream Cheese
1 cup suger
1 tsp. vanilla
1 cup sour cream
4 eggs

Preheat oven to 325°F (160°C). Place 30 of the cookies in plastic bag. Flatten and seal bag. Crush cookies. Place crumbs in medium bowl. Add butter and mix well. Press firmly onto bottom of baking pan.
Beat cream cheese, sugar and vanilla in large bowl (blender). Add sour cream and mix well. Add eggs, one at a time, beating just until blended after each addiction. Chop remaining 15 cookies. Gently stir 1 1/2 cups of the chopped cookies into cheesecake batter. pour over curst. Sprinkle with remaining chopped cookies.

Bake 45 minutes or until centre is almost set. Cool.