Symbolism, Imagery, Allegory
In our lives, chocolate is symbolic of about half a million things. We eat chocolate when we're celebrating—no better way to congratulate yourself on getting a year older than eating some Phish Food ice cream. We eat chocolate when we're feeling sad—what else are you going to do when your heart is broken, right? We eat chocolate when we're bored—nothing makes plane travel more bearable than a package of M&Ms.
Ponyboy is frequently seen eating candy bars (we knew we related to this kid on many levels), and there's really nothing very symbolic about a kid eating candy.
But when we add chocolate cake for breakfast into the mix, the treat does take on a bittersweet (pun intended) symbolism. When Pony is describing his breakfast-making activities on the morning after his return from Jay Mountain, he tells us,
All three of us like chocolate cake for breakfast. Mom had never allowed it with ham and eggs, but Darry let Soda talk him into it. We really didn't have to twist his arm; Darry loves chocolate cake as much as we do. (7.23)
So, in some ways, chocolate—specifically chocolate cake—becomes a symbol of the Curtis boys' loss of their parents. What kid hasn't thought something like, "if Mom and Dad weren't around, I'd eat chocolate cake for breakfast everyday"?
Well, if it meant the death of Mom and Dad, chocolate cake for breakfast wouldn't be such a great thing, would it? Pony makes sure we understand that Darry only lets them eat the cake with the more nutritious ham and eggs, and that Darry provides nutritious balanced meals.
The cake symbolizes their loss, but also Darry's desire to give his brothers something, anything to take away some of the sting from their loss. The brothers reach for sweetness in an increasingly bitter time in their lives.