Right and wrong

Ever vigilant in my undercover work for the grammar police, I spotted this in a Cobbs Coffee bar. Now one is right and one is wrong. Can you guess? Well, since a smoothie is cold, it cannot melt. It can meld though. Whilst the other one, may presume to be incorrect, but, contrary to the common spelling, the word gateau is correct. The addition of the letter 'x' is used to pluralise it.