I like onigiri, Japanese rice balls. A handful of rice with something savory dabbed in the middle wrapped in sushi nori. I first tried it with miso, but my favorite is traditional umeboshi paste. It's made from a sour pickled plum, a unique sour salty taste I love. In Japan umeboshi are also used for upset stomach, even hangovers, so they taste particularly good late on a hot day of racing when the sweet stuff starts to annoy.
I also like Allen Lim style rice cakes.