First, measure out all ingredients. The last thing you want is for your homemade caramel to burn, so ensure everything is measured and both the butter and cream are at the right temperature.
Melt the sugar. Place 1 cup (200g) sugar in a heavy-bottomed saucepan over medium heat. Stir continuously with a heatproof spatula or wooden spoon as it melts into a deep amber liquid. Be patient – the sugar will clump before liquefying. This takes about 5-7 minutes.
Add butter. Once sugar is fully melted and amber in color, carefully whisk in 6 Tbsp (84g) room-temperature butter. It will bubble vigorously – keep whisking until incorporated. If you notice the sugar beginning to clump again, remove the pan from the heat, then continue whisking until it’s smooth. Return to the heat.
Add cream. Slowly pour in ½ cup (118ml) room-temperature or warmed heavy cream while whisking constantly. Again, the caramel will bubble up – just keep whisking until smooth.
Season with salt. Remove from heat and whisk in 1 tsp flaky sea salt.
Cool. Let caramel cool in the pan for at least 20 minutes before transferring to a jar. It may look thin, but it will thicken as it cools. This can be made days in advance!
Make the crust. Preheat an oven to 325°F (163°C). Wrap the bottom and sides of a 7-inch springform pan tightly with heavy duty aluminum foil (trust me on the ‘heavy duty’ part), then grease the inside. Combine 1½ cups (180g) graham cracker crumbs, 3 Tbsp (42g) melted butter, 2 Tbsp (24g) sugar, and a pinch of kosher salt in a small bowl, then mix well. Pour into the prepared pan, then press into an even layer along the bottom, reaching up slightly less than halfway on the sides. Bake for 10 minutes, or until the crust turns a deep golden brown. Remove from the oven and let cool while you make the filling.
Make the filling. Beat 16 oz (454g) cream cheese, ⅔ cup (130g) sugar, and 2 tsp vanilla extract in the bowl of a stand mixer until smooth and creamy, about 2 minutes. Scrape down the sides, add 2 eggs, then beat on medium-low until fully incorporated and fluffy. Pour the cheesecake mixture over the cooled crust.
Add salted caramel. Pour ¼ cup of salted caramel on top of the cheesecake, then use a knife to swirl into the batter.
Bake the cheesecake. Place the springform pan in a large baking pan, then fill about 1-inch with hot water. Bake for 45-50 minutes, or until the edges of the cheesecake turn golden brown and pull away from the sides. The middle of the cheesecake will be a little jiggly.
Cool in the oven. Turn the oven off, then crack the door just slightly. Let the cheesecake cool for 1 hour in the oven, then remove and continue to cool to room temperature on the counter. Refrigerate for 4 hours or overnight before serving (with whipped cream, if you like!).