Listen closey to the scene where Kate is getting out of Sawyer's bed in the morning planning to go back to the beach. They're both sort of arguing and when Kate says "Goodbye, James", Sawyer clearly replies with, "Don't make this about me, cake".

Thought it was pretty funny

Well, actually it sounds like "cake" but all the official transcripts give it as "Kate" so I presume it's the second one.
Moreover, Sawyer uses to call her by her name, no nicknames, when he's angry or pissed off.

chrisus jrist,imagine if we had to figure out what kinda cake they were referring to...!!!
was it almond butter or was it carrot cake?? ? HIDDEN SIGNIFICANCE OF CARROTS?please noooo!!!!
diggin through old grumps recipe books and surfin endlessly on pastry sites!!!!

thankgod its not cake!