Preheat the oven to 350ºF. 

Place the chocolate cookies in a food processor and process until they are fine crumbs.  Add the melted butter and brown sugar and pulse a few times to combine.  Pour into the bottom of a 9-inch springform pan.  Use a measuring cup to press the crust into the bottom and 1-inch up the sides of the pan.

Place the pan on a baking sheet and place in the oven.  Bake for 10 minutes.  Remove from the oven and allow to cool slightly.

In the bowl of a mixer, beat the cream cheese until smooth.  Gradually beat in the sugar, scraping the bowl as needed.  Add the eggs, one by one, beating after each addition.  Add the vanilla and stir to combine.

Pour the cheesecake mixture into the crust.  Return to the oven** and bake until the cheesecake is set around the edges and slightly wobbly in the center, about 50 minutes. 

While the cheesecake is baking, make the sour cream topping. In a bowl, beat the sour cream.  Gradually add the sugar, then the vanilla.

Remove the cheesecake from the oven and increase the oven temperature to 500ºF.  Spread the sour cream topping over the cheesecake, then return to the oven and bake for an additional 5 minutes.  Turn off the oven and open the oven door slightly.  Allow the cheesecake to come to room temperature, then cover and refrigerate until cooled through.

Serve topped with your favorite cheesecake toppings.