Prepare the Caramel Sauce: Pour the prepared salted caramel into a heatproof container and place it in the refrigerator while you prepare the cheesecake.
Prepare the Pan: Preheat the oven to 350°F and grease the bottom and sides of a 9-inch springform pan. If desired, line the bottom with parchment paper.
Mix the Crust: Combine the ground gingersnap cookies, granulated sugar, and melted butter in a bowl. Stir until the crumbs are evenly moistened.
Shape the Crust: Press the crumb mixture firmly into the bottom of the prepared springform pan and halfway up its sides.
Bake the Crust: Bake the crust for 8–10 minutes, then set it aside to cool while preparing the cheesecake filling.
Lower the Oven Temperature: Reduce the oven temperature to 325°F and place a large roasting pan on the bottom rack.
Make the Cheesecake Base: Using a stand mixer fitted with the paddle attachment or a hand mixer, combine the room-temperature cream cheese, granulated sugar, and flour on low speed just until smooth. Scrape down the bowl.
Heat the Water Bath: Place a medium pot of water on the stovetop and bring it to a boil for the cheesecake's water bath.
Add the Eggs: Mix the room-temperature eggs into the cream cheese mixture one at a time, scraping down the bowl halfway through.
Finish the Filling: Scrape down the bowl again, then mix in the vanilla bean paste, sour cream, and 1/3 cup (82 g) cooled salted caramel sauce.
Blend by Hand: Use a rubber spatula to give the batter one final thorough mix by hand, making sure everything is evenly combined.
Fill the Crust: Pour the cheesecake batter over the cooled crust, then gently drop the pan against the counter a couple of times to release air bubbles.
Set Up the Water Bath: Once the water is boiling, carefully pour it into the roasting pan on the bottom rack, then place the cheesecake on the middle rack directly above it.
Bake the Cheesecake: Bake for 1 hour 20 minutes. The cheesecake is ready when the edges have puffed up and the center gives a tight jiggle when the pan is gently nudged.
Cool in the Oven: Turn off the oven and leave the cheesecake inside with the door cracked open for 45 minutes.
Add the Caramel Topping: Pour the remaining caramel sauce over the cheesecake before refrigerating. If the caramel has become too thick to pour, microwave it for about 30 seconds to loosen it.
Chill Until Set: Refrigerate the cheesecake for at least 4 hours to set, preferably overnight.
Finish with Sea Salt: Sprinkle a pinch of flaky sea salt over the cheesecake just before serving.
Serve Slightly Chilled: Serve the cheesecake slightly chilled so the caramel topping holds its shape.
Store Properly: Keep any remaining cheesecake in an airtight container in the refrigerator.