Step 1: Prepare the yellow cake mix according to package directions. Pour the batter into a greased 9x13 inch baking pan and bake as instructed. Once baked, remove from oven and let cool completely on a wire rack. Once cooled, use the handle of a wooden spoon or a fork to poke holes all over the cake, ensuring they go through to the bottom.
Step 2: In a large bowl, use a hand mixer to beat the softened cream cheese until light and fluffy. Gradually add the powdered sugar, mixing until well combined and smooth. Fold in half of the thawed whipped topping until no streaks remain. Spread this cream cheese mixture evenly over the cooled, poked cake base.
Step 3: In a separate bowl, whisk together the instant vanilla pudding mixes with the cold milk for about 2 minutes, or until the mixture begins to thicken. Pour this thickened pudding mixture over the cream cheese layer, gently spreading it to cover completely.
Step 4: Carefully spread the remaining half of the whipped topping generously over the pudding layer, creating a smooth, airy top. For an optional garnish, sprinkle with toasted coconut flakes, chocolate shavings, or a light dusting of cocoa powder.
Step 5: Cover the pan loosely with plastic wrap and refrigerate for a minimum of 4 hours, or preferably overnight. This allows all the layers to set properly and the flavors to meld beautifully. When ready to serve, cut into squares and enjoy your divine Heaven on Earth Cake!