Preheat your oven to 350°F (175°C) and grease a 9x13 inch pan with non-stick spray or butter.

In a large mixing bowl, combine the ricotta cheese, granulated sugar, and vanilla extract, mixing until smooth.

Gradually add the eggs to the ricotta mixture, mixing well after each addition.

In another bowl, prepare the devil's food cake mix according to package instructions.

Pour the cake batter into the greased pan and spread it evenly.

Gently spoon the ricotta mixture over the chocolate layer without stirring.

Place the pan in the oven and bake for 1 hour to 1 hour and 10 minutes. Check for doneness using a toothpick.

Let the cake cool in the pan on a wire rack until it reaches room temperature.

In a mixing bowl, whisk together the chocolate pudding mix and whole milk until thickened, then fold in the whipped topping.

Spread the pudding mixture evenly over the cooled cake and refrigerate for at least 4 hours.