1. Preheat the oven to 325ºF/165°C.

For the Oreo cookie base:

1. Line the bottom of a 9-inch springform pan with aluminum foil, tuck it underneath the pan bottom, assemble the cake pan, then pull up the foil around the sides of the pan. This makes it a snap to unmold.
2. Butter or spray (with baking spray) the sides of the pan.
3. Melt butter. Add ground cookies and mix with a spoon. Or mix directly in the processor if you used it to grind the cookies.
4. Put the mixture in the prepared pan and press firmly onto the bottom.
5. Bake it for 10 minutes and reserve until the filling is ready, or refrigerate while making the filling (without baking). I like to bake it because it firms up the base. But both ways work. Don't turn off the oven.

For the cheesecake mixture:

1. Beat cream cheese in a large bowl until smooth. Add sour cream and mix.
2. Gradually add sugar and beat on medium speed until sugar dissolves.
3. Add eggs, one at a time, mixing until just incorporated and scraping down the sides of the bowl after each addition. At this point, I change to a hand beater because I don't want to incorporate extra air into the mixture, so I don't beat it, simply mix it well. 
4. Add vanilla and cream to the cream cheese mixture, stirring to incorporate.
5. Pour batter into the prepared pan.
6. Cut cookies into small pieces (I use a kitchen knife). You will have some chunks of Oreos and some crumbs.
7. Scatter oreo pieces and crumbs on top of the cheese batter.
8. Take a spoon and lightly push crumbs into the cheese mixture until barely covered. That way the end result is a distinctive cookie crust, cheese layer, and cookie crumbs on top.
9. Bake for 10 minutes, turn the oven down to 300°F (150ºC) and bake for another 60 minutes (at this point the cheesecake should still jiggle quite a lot in the center). We don't use a water bath.
10. Turn the oven off and, without opening the door, let the cheesecake inside for 1 hour. Take it out, very carefully run a smooth-bladed knife around the edges (it loosens the cheesecake as it shrinks a little while cooling down, and can prevent some cracks), and cool to room temperature on a wire rack. The chopped cookies on top sink slightly into the batter, and some cracks will naturally (and probably) appear. The topping covers it. 
11. Refrigerate in the pan for at least 8 hours (1 day makes it creamier in my experience), wrapping it in plastic. 
12. To remove from pan: unwrap, run a smooth bladed knife around the edges in case it's stuck, open the springform pan and remove, lift foil, and place your palm between the metal pan and the foil. Carefully lift the whole cheesecake, and, holding it in one hand, push the foil down and lift the cake with your other hand.
13. Place it carefully on the serving plate, sprinkle crushed Oreo cookies on top of the cheesecake, and drizzle with chocolate ganache (instructions below). 
14. Refrigerate leftovers covered with plastic wrap or in an airtight container.

For the ganache:

1. Chop chocolate and place in a small bowl.
2. Bring cream to a boil, pour over chocolate, and stir until very smooth.
3. Pour ganache over the cheesecake right before serving (after it has stayed in the fridge for at least 8 hours). You can do this with a pitcher (as shown in the video) or by drizzling it with a fork or spoon.