This won't do if you want to convince a liberal with it, because their biggest reason to go after gun rights is concerns about safety believing what individuals or groups of individuals can pull off with guns is more dangerous than what the government can pull of once it gets crazy for power, meanwhile cake is absolutely harmless so it would complicate drawing parallels between cakes and gun rights.
Also it won't convince people who know how cakes work, because if you're such a retard that you stare at your cake instead of eating it already, you deserve somebody else eating the whole thing for you.