1. Preparation:

Preheat your oven to 350°F (175°C) and lightly grease a 9×13 inch baking pan.

2. Cake Base Construction:

In a mixing bowl, combine the chocolate cake mix, 1/2 cup melted butter, and 1 egg until a thick batter forms. Press the batter evenly across the bottom of the greased pan.

3. Filling Creation:

In another mixing bowl, blend cream cheese and peanut butter until smooth. Add eggs, vanilla extract, and melted butter, mixing until well combined. Gradually incorporate powdered sugar until smooth, then gently fold in the chocolate chips.

4. Assembly:

Spread the peanut butter filling over the cake base in the pan, ensuring even coverage.

5. Baking:

Bake in the preheated oven for 40-50 minutes, or until the edges are firm and the center is slightly soft and gooey. Avoid overbaking for optimal texture.

6. Cooling:

Allow the cake to cool in the pan. As it cools, the center will set while retaining its delightful gooeyness.

7. Peanut Butter Ganache Topping Preparation:

In a small saucepan, heat the heavy cream until it begins to simmer. Pour the hot cream over the chopped chocolate and peanut butter in a heatproof bowl. Let it sit for 1-2 minutes, then add the butter and stir until smooth and glossy.

8. Serving:

Once the cake has cooled, pour the peanut butter ganache over the top, spreading it evenly. Allow the ganache to set slightly before slicing into squares. Serve at room temperature or chilled, as desired.