Preheat your oven to 350°F (175°C). Prepare your brownie mix according to the package instructions, or use a homemade recipe. Pour the batter into a greased 9-inch springform pan and bake for 25–30 minutes until the edges are set but the center jiggles slightly.

Let the brownie base cool completely while you make the cheesecake layer.

In a large mixing bowl, beat 24 ounces of softened cream cheese and 1 cup of granulated sugar together until smooth and creamy, about 2–3 minutes. Add in 3 large room-temperature eggs one at a time, mixing well after each addition. Incorporate 1 tablespoon of vanilla extract and 1 cup of sour cream, blending until velvety and fully combined.

Pour the cheesecake mixture evenly over the cooled brownie base. Drizzle caramel sauce on top of the cheesecake and use a knife or skewer to swirl it in for a marbled effect.

Place in the preheated oven and bake for 45–50 minutes. The cheesecake should be just set but jiggle slightly in the center. Avoid overbaking.

After baking, turn off the oven and crack the door to let the cheesecake cool gradually for about 1 hour. Refrigerate for at least 4 hours, or preferably overnight.

Carefully remove from the springform pan. Garnish with extra caramel drizzle, if desired, and slice into pieces. Serve chilled with whipped cream or vanilla ice cream.