Prepare a 9-inch springform pan that is at least 3 inches tall by spraying it with non-stick baking spray and lining the bottom with parchment paper.
Brownie Layer
In a microwave or on the stovetop, melt the chocolate and butter until smooth.
Stir in the sugar and let the mixture cool slightly. Add the eggs one at a time, stirring until fully incorporated. Stir in the vanilla extract.
Sift the flour, cocoa powder, salt, and baking powder over the chocolate mixture. Gently fold until fully combined.
Spread the batter evenly in the prepared springform pan.
Bake for 25–30 minutes. The brownie will appear slightly underbake, this is normal as it will finish baking with the cheesecake layer.
Remove from the oven and set aside. (You can prepare the cheesecake batter while the brownie layer bakes.)
Cheesecake Layer
In a large mixing bowl, beat the cream cheese and sugar on medium speed until smooth and creamy.
Mix in the sour cream, vanilla, and salt until fully incorporated.
Whisk the eggs and add them one at a time, mixing well between each addition. Make sure to scrape down the sides and bottom of the bowl to ensure the batter is well blended.
Layer and Swirl: Pour half of the cheesecake batter over the brownie layer in the prepared pan.
Dollop half of the caramel sauce and half of the chocolate sauce over the cheesecake batter. Use a knife to gently swirl the sauces into the batter.
Pour the remaining cheesecake batter on top. Repeat with the remaining caramel and chocolate sauces, swirling them gently with a knife.
Prepare the Water Bath: Place the springform pan inside a disposable crockpot liner or large turkey oven bag. Alternatively, wrap the pan with several layers of aluminum foil but I find the aluminum foil tends to rip and leak so I prefer using the oven bag.
Place the springform pan in a larger baking pan and pour boiling water into the larger pan until it reaches about halfway up the sides of the springform pan.
Bake: Bake in the water bath for 50 to 65 minutes or until the edges look set and the center has a slight jiggle (see notes). Turn off the oven and crack the door open slightly (use a wooden spoon to prop it open if necessary). Let the cheesecake cool in the oven for 30 to 50 minutes.
Cooling and Serving
Carefully remove the springform pan from the water bath and unwrap it. Let it cool to room temperature on a wire rack.
Refrigerate the cheesecake for at least 4 hours or overnight.
Run a knife along the edges of the springform pan to loosen the cheesecake before removing the sides.
Serve with additional chocolate and caramel sauce and garnish with whipped cream and pecans if desired.
Notes
Use a 9-inch springform pan that is at least 3-inches tall to ensure there’s enough room for the brownie and cheesecake layers without overflowing.
Springform pans can leak when placed in a water bath. To avoid this, I use a disposable crockpot liner or a large turkey oven bag to seal the pan securely. If you use aluminum foil, wrap the pan with several layers to prevent leaks.
The brownie layer will look slightly underbaked when you take it out of the oven. It will continue baking when you add the cheesecake layer.
When swirling the caramel and chocolate sauces, avoid overmixing. Swirl gently with a knife to create a marbled effect without fully blending the sauces into the cheesecake batter.
For the cheesecake layer, make sure the cream cheese, eggs, and sour cream are at room temperature. This helps them blend smoothly and prevents lumps.
After baking, let the cheesecake cool in the oven with the door cracked for at least 30 minutes. This gradual cooling helps prevent cracks on the surface.
For neat slices, run a sharp knife under hot water, dry it, and slice. Wipe the knife clean after each cut.
Store the cheesecake in the refrigerator, covered, for up to 5 days. You can also freeze in a freezer-safe bag or container.
You can use store-bought sauces or make your own. Just ensure they’re pourable for easy swirling.
When your cheesecake is done, the edges will look set and the center will have a slight jiggle when you tap the side of the pan. For a more precise check, use a thermometer to measure the internal temperature. It should read 150ºF in the center when fully baked.