1. Preheat oven to 325°F (163°C). Line a 9-inch (23cm) springform pan with parchment paper in the bottom and grease the sides.
2. Combine the crust ingredients in a small bowl. Press the mixture into the bottom and up the sides of the springform pan.
3. Bake the crust for 10 minutes, then set aside to cool.
4. Cover the outsides of the pan with aluminum foil so that water from the water bath cannot get in. Set prepared pan aside.

CHEESECAKE FILLING AND TOPPING

5. Reduce oven to 300°F (148°C).
6. In a large mixer bowl, mix the cream cheese, sugars and flour until well combined (Use low speed to keep less air from getting into the batter, which can cause cracks). Scrape down the sides of the bowl.
7. Add the sour cream, then the vanilla, mixing on low speed until well combined.
8. Add the eggs one at a time, beating slowly and scraping the sides of the bowl after each addition.
9. Stir in the chocolate chips.
10. Pour the cheesecake filling into crust and spread into an even layer.
11. Place springform pan (covered with aluminum foil) inside another larger pan. Fill the larger pan with enough warm water to go about halfway up the sides of the springform pan. The water should not go above the top edge of the aluminum foil on the springform pan.
12. Bake for 1 hour and 10 minutes.
13. Turn off heat and leave cheesecake in oven with door closed for 30 minutes.
14. Crack oven door and leave the cheesecake in the oven for about 30 minutes.
15. Remove cheesecake from oven and remove the water bath. Chill in the fridge until firm, 5-6 hours or overnight.

CARAMEL SAUCE AND ASSEMBLY

16. Combine all ingredients in a medium sauce pan.
17. Heat on medium-low until sugar is melted, then turn heat to medium-high to bring to a boil.
18. Boil for 3 minutes, stirring occasionally, then remove from heat and immediately pour into a heat-proof glass bowl.
19. Let the sauce cool for 15 minutes or so, then pour over the top of the cheesecake and spread evenly.
20. Top the cheesecake with some additional chocolate chips.
21. Refrigerate cheesecake until ready to serve. Cheesecake is best when eaten within 3-4 days. Keep the cheesecake well covered in the refrigerator in a cake carrier or wrapped with plastic wrap. You can use toothpicks to prop up the plastic wrap and prevent it from sticking to the top of the cake.