yes, fans tend to like the idea that gaara loves cookies, but in truth his favorite food is salted tongue and gizzard XP (eeeeeeeeeeeeeeeeeew)

though this could also be entirely fan-based made up material too, we really have no Idea officially what gaara's favorite food is. This idea simply came from an artist that i find to be quite credible.
but the Idea that he would like somthing like that makes sense. he lives in the desert! where things are very warm, food spoils easily and quickly. Spicey and dried (very salty foods (spicy foods too)) foods would probably be common because things that are dried and/or are spicy tend to keep bacteria and other stuff that would make it spoil away from the food item. ( that is also were most strong spices originated from too (from places near the equator (very warm places))).
;p thats my logic for ya.