• Begin boiling water in a large pot to use for the water bath.
• Preheat oven to 350°F. Spray a 9" springform pan generously with non-stick cooking spray and wrap multiple layers of heavy-duty aluminum foil tightly around the bottom and up the sides. Make sure it is wrapped very securely with several layers of foil so that no water from the water bath is able to seep in.

Make the Caramel Sauce:

• Add the sugar and water to a large, clean pot and place over medium-low heat. Stir until the sugar is dissolved.
• Once the sugar has dissolved, stop stirring completely and crank the heat up to medium. Watch closely as the sugar syrup turns from clear, to pale yellow, to a dark amber color. Have your heavy cream ready.
• As soon as the sugar is dark amber in color, remove from heat and slowly drizzle in the heavy cream, whisking constantly. Do this carefully, the sauce will bubble violently at first, and then settle after a few seconds as the temperature evens out.
• Return to the stovetop over low heat and whisk in the butter and salt. Remove from heat and let cool. The caramel sauce will get thicken as it cools.

Make the Graham Cracker Crust:

• Combine the graham cracker crumbs, sugar, and melted butter in a large bowl or in the bowl of a food processor.
• Press the crust into the bottom of the prepared springform pan and slightly up the sides. Prebake the crust for 10 minutes.

Make the Cheesecake Filling:

• Use a hand-held mixer to beat the room temperature cream cheese, sugar, and flour together until smooth and creamy with no lumps. Mix in the sour cream and vanilla extract. Add room temperature eggs, 1 at a time, and mix until just combined after each.
• Gently fold ½ cup of the caramel sauce into the cheesecake batter. Reserve the remaining caramel sauce for topping the cheesecake. Pour the filling into the graham cracker crust.
• Place the cheesecake in a larger baking pan with high sides and carefully pour the boiling water in, going up about 2 inches around the sides of the springform pan.
• Bake the cheesecake for 1 hour and 20 minutes, it should be only slightly wobbly in the center. Avoid opening the oven door while the cheesecake bakes.
• When the cheesecake is done, turn the oven off and crack the door slightly. Allow the cheesecake to cool in the oven for 1 hour, then remove from the water bath and let cool at room temperature before refrigerating. Cover and refrigerate for at least 3 hours or overnight. Spread more caramel sauce over the top of the cheesecake once cooled.
• Keep refrigerated until ready to serve. Drizzle more sauce over individual slices, if desired.