Preheat the oven to 325ºF. Combine graham cracker crumbs, toffee bits, salt, granulated sugar, and melted butter in a large bowl. Press into a 9-inch springform pan, all the way up the sides, using the bottom of a drinking glass or measuring cup. Sprinkle with chocolate chips. Set the pan on a baking sheet and bake for about 5 minutes until chocolate chips are melty. Smooth them out with an offset spatula. Place in the freezer to chill.

In the bowl of a stand mixer fitted with a paddle attachment, mix cream cheese, sugar, and sour cream on medium speed for 3 minutes. Add vanilla extract and caramel sauce, and mix on medium speed for another minute. Reduce speed to low and add eggs, one at a time, mixing until combined. Pour filling into chilled crust.

Wrap the springform pan in wet dishtowels to help the cheesecake cook slowly and evenly. Bake for 1 hour and 20 minutes. The center should still be jiggly. Remove from the oven and cool on a cooling rack for 2 hours before refrigerating. Refrigerate for 6 hours or overnight.

In the bowl of a stand mixer fitted with a whisk attachment, whip whipping cream until soft peaks form. Add powdered sugar and continue whipping on high until stiff peaks form. In a medium bowl, combine caramel and 1/2 cup of toffee. Place toffee mixture on top of chilled cheesecake and spread out with an offset spatula. Pipe whipped cream along the edge and garnish with more toffee bits.