I didn't read it as if they switched away from rice cakes but that they used brownies in another event. Rice cakes in general are pretty great as on-bike nutrition and used by world tour teams.

EF-Nippo's recipe for example: https://www.efprocycling.com/team-recipe-on-the-bike-rice-ca...

Rice cakes can be calorie dense. You use cream cheese and add molasses/honey as well when you're making them.