Ponyboy is frequently seen eating candy bars, 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 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 loss 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.