Preheat your oven to 325°F (165°C). In a medium bowl, combine the chocolate graham cracker crumbs and 1/4 cup of sugar. Stir in the melted butter until the mixture resembles wet sand and holds together when pressed. Firmly press this mixture into the bottom and about halfway up the sides of a 9-inch springform pan.
In a large mixing bowl, beat the softened cream cheese and 1 cup of sugar with an electric mixer on medium speed until the mixture is completely smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl with a spatula to ensure even mixing.
Add the eggs one at a time, beating on low speed just until each egg is incorporated before adding the next. Mix in the vanilla extract and sour cream until the batter is uniform. Be careful not to overmix after adding the eggs.
Pour about two-thirds of the cheesecake batter over the prepared crust. Sprinkle the chocolate chips and chopped pecans evenly over the batter. Drizzle the caramel sauce over the top. Carefully spoon the remaining cheesecake batter over the caramel and nuts, spreading it gently to cover.
Place the springform pan on a baking sheet and bake for 55-65 minutes, or until the edges are set and the center still has a slight jiggle when gently shaken. Turn off the oven, crack the door open, and let the cheesecake cool inside for 1 hour before removing it to cool completely on a wire rack. Chill in the refrigerator for at least 4 hours, or preferably overnight.
Before serving, run a thin knife around the edge of the pan to loosen the cheesecake, then release the springform collar. Drizzle the warmed hot fudge sauce over the top of the chilled cheesecake.