Bake the Cake:
Preheat the oven according to the instructions on the cake mix box. Grease a 9×13-inch baking dish. Prepare and bake the yellow cake as directed on the box. Once baked, allow the cake to cool for about 15 minutes. The cake should be slightly warm when you start poking holes into it.
Poke the Holes:
Using the handle of a wooden spoon or a straw, poke holes across the top of the cake, going all the way to the bottom. This is the key step that allows the pudding to soak into the cake, creating a moist and flavorful texture throughout.
Mix the Pudding:
In a bowl, whisk together the two boxes of vanilla pudding mix and the cold milk for about 2 minutes, until the pudding begins to thicken slightly.
Fill and Chill:
Pour the pudding mixture slowly and evenly over the cake, making sure it fills the holes you created. Gently press the pudding into the holes with a spatula to ensure it soaks in. Smooth the top with a spatula to evenly distribute the pudding. Refrigerate the cake for at least 1 hour to allow it to set.
Make the Chocolate Ganache:
In a small saucepan, heat the heavy cream over medium heat until it begins to simmer. Remove from heat and pour the semi-sweet chocolate chips into the warm cream. Let it sit for about 1 minute, then stir until smooth. For a glossy finish, stir in the corn syrup and vanilla extract.
Top the Cake:
Once the cake has chilled and the pudding is set, pour the chocolate ganache evenly over the top of the cake, spreading it out gently with a spatula to cover the entire surface. The ganache should flow smoothly and create a rich, shiny topping.
Chill and Serve:
Allow the cake to chill in the refrigerator for at least 1 more hour, or until ready to serve. Slice and enjoy the delicious layers of moist cake, creamy pudding, and decadent chocolate ganache.
