Preheat your oven to 350°F (175°C). Melt 1 cup of unsalted butter in a medium saucepan over low heat. Whisk in 2 cups of granulated sugar until well combined. Allow to cool slightly before adding 4 large eggs and 2 teaspoons of vanilla extract, mixing until smooth.

In a separate bowl, sift together 1 cup of all-purpose flour, ¾ cup of cocoa powder, and ½ teaspoon of salt. Gently fold dry ingredients into the wet mixture.

Pour the brownie batter into a greased 9-inch springform pan and bake for 25-30 minutes. Check doneness with a toothpick. Let cool completely.

In a large bowl, blend 16 ounces of softened cream cheese with ¾ cup of granulated sugar until creamy. Add 2 large eggs, 1 teaspoon of vanilla extract, and ½ cup of sour cream. Mix until smooth.

Pour the cheesecake mixture over the cooled brownie layer. Bake for 30-35 minutes until the cheesecake is set but still slightly wobbly in the center.

In a saucepan, melt 1 cup of granulated sugar over medium heat until golden amber. Stir in 6 tablespoons of butter and ½ cup of heavy cream until smooth, then add 1 teaspoon of sea salt. Set aside.

Let the cheesecake cool for about 1 hour. Drizzle with caramel sauce. Refrigerate for at least 2 hours before serving.