Preheat your oven to 350°F (175°C). Prepare the fudge brownie mix as per package instructions, incorporating eggs, oil, water, and the optional espresso powder.

Pour the brownie batter into a greased 9-inch springform pan. Bake for 20-22 minutes or until set. Let it cool completely.

Reduce the oven temperature to 325°F (165°C). In a mixing bowl, beat together cream cheese and granulated sugar until smooth. Gradually add the eggs, one at a time. Then mix in the sour cream, vanilla extract, and flour until well blended.

Pour the cheesecake mixture over the cooled brownie layer. Wrap the springform pan in aluminum foil and place it inside a larger pan filled halfway with hot water.

Bake for 55-65 minutes, until the center is slightly jiggly. Turn off the oven and leave the door ajar, allowing it to cool for one hour.

Refrigerate the cheesecake for at least 6 hours or overnight.

Toast the pecans in a dry skillet for 3-4 minutes until fragrant. Warm the caramel sauce in a separate container.

Prepare chocolate ganache by heating the heavy cream and pouring it over the semi-sweet chocolate chips. Whisk until smooth.

Top the cheesecake with the warm caramel sauce, chocolate ganache, and toasted pecans. Chill for an additional 30 minutes before slicing.