1. To make the cookie bottom, preheat the oven to 350°F (176°C). Place parchment paper in the bottom of a 9 inch springform pan and grease the sides.
2. Cream the butter and sugars together until light and fluffy, about 3-4 minutes.
3. Mix in egg and vanilla extract until combined.
4. In a separate bowl, combine the flour, baking soda, baking powder and salt.
5. Add the dry ingredients to the butter mixture and mix until well combined.
6. Stir in the chocolate chips. The cookie dough will be thick.
7. Press the dough evenly into the springform pan.
8. Bake for 16-18 minutes or until the edges are slightly golden.
9. Remove from oven and allow to cool completely in the pan.
10. To make the cheesecake filling, add the cream cheese, sugar and cocoa powder to a large mixer bowl and beat until well combined and smooth.
11. Add the vanilla extract and melted chocolate and mix until well combined. Set aside.
12. In another large mixer bowl, add the heavy whipping cream and powdered sugar. Whip on high speed until stiff peaks form.
13. Add about 1/3 of the whipped cream to the cream cheese mixture and fold carefully to combine.
14. Add the remaining whipped cream and fold carefully until well combined.
15. Add the chopped cookies and fold to combine.
16. To put the cheesecake together, first add chocolate chips cookies around the sides of the pan, sitting on top of the edge of the cookie bottom. If you have trouble getting them to stand up, spoon small amounts of cheesecake filling up against the cookies to help keep them in place.
17. Add the remaining cheesecake filling and spread into an even layer.
18. Refrigerate cheesecake until firm, 5-6 hours or overnight.
19. To finish off the cheesecake, make the chocolate whipped cream. Add the heavy whipping cream, powdered sugar, cocoa powder and vanilla extract to a large mixer bowl and whip on high speed until stiff peaks form.
20. Remove the cheesecake from the springform pan and pipe swirls of whipped cream around the edge.
21. Top the cheesecake with additional cookies and mini chocolate chips.
22. Refrigerate cheesecake until ready to serve. Cheesecake is best for 3-4 days.