Preheat oven to 350°F and set aside a 9-inch springform pan.
Arrange 14 Oreo cookies so they're standing up along the inside edge of the springform pan.
In a medium bowl, beat cream cheese with a hand mixer until fluffy. Gradually add sugar and beat until combined. Then add the vanilla, eggs, sour cream, mixing well after each addition.
Using a large wooden spoon, stir the 6 chopped Oreo cookies into the cream cheese mixture. Then spoon the batter into the pan, taking care not to topple the oreos.
Bake for 25-30 min until a cake tester or toothpick inserted in the middle comes out clean.
Remove from oven and allow to cool for at least one hour.
Arrange the optional raspberries next to the oreos to form a circle.
Chill until serving. Then carefully release the outside of the springform pan to expose the Oreos.