Preheat the oven to 350 degrees F. Grease a 9x13 inch baking pan and set aside.

In a large bowl, combine the chocolate cake mix, eggs, vegetable oil, and water. Beat with an electric mixer on medium speed for 2 minutes until smooth and well combined. Pour the batter into the prepared pan.

Bake for 28-30 minutes or until a toothpick inserted in the center comes out clean. Let the cake cool completely in the pan.

For the cream filling: Beat the softened cream cheese and butter together until smooth and fluffy, about 2 minutes. Add the powdered sugar one cup at a time, mixing on low after each addition. Add the vanilla extract and beat on medium-high for 1 minute until light and creamy.

Spread the cream filling evenly over the cooled cake. Refrigerate for 15 minutes while you make the ganache.

For the chocolate ganache: Heat the heavy cream in a small saucepan until it just begins to simmer. Pour it over the chocolate chips in a heatproof bowl. Let it sit for 2 minutes, then stir until completely smooth. Stir in the 2 tablespoons of butter until melted and glossy.

Pour the ganache over the cream filling layer and spread it evenly with an offset spatula. Refrigerate for at least 30 minutes before slicing and serving.