Preheat oven to 350°F and grease a 9×13-inch baking dish.

In a bowl, mix chocolate cake mix, 1 egg, and melted butter until combined.

Press the mixture evenly into the bottom of the prepared baking dish.

In another bowl, beat cream cheese until smooth.

Add remaining eggs, cocoa powder, vanilla extract, and powdered sugar and mix until smooth.

Spread the cream cheese mixture evenly over the cake base.

Bake for 40–45 minutes until edges are set and center remains soft.

Cool for at least 15 minutes before slicing and serving.