if you have a lot to lose, and you don't want the risk, you smugle.
I unwittingly found myself "smuggling" stuff (" ") on flights several times and did not get caught. but if its not just a customs issue where I pay a penalty and that's it - if I'm risking jail or worse, I would never do it intentionally without a really good reason (like the example above), and then also using the least risky method I can think of. given that, cake is kind of suspect... like baking contraband into a loaf of bread.