The sequel mentions Harry's canon love of Treacle Tart.
Carol Danvers is also noted as having a particular weakness for ice cream, with her uncle claiming that her puppy dog eyes never got him to let her have more ice cream (rendered particularly unconvincing by his sister - Carol's mother - wryly observing that he'd let Carol have or do more or less anything that her Jerkass father didn't want her to have/do, more or less out of spite). In the sequel, she ends up going through a 'Thor-sized' tub of Rocky Road as Comfort Food/bonding with Steve.
Code Geass: Paladins of Voltron: Pizza, duh. One of the first things C.C. does when the team returns to Earth is using a Pod to get boxes of Pizza Hut pizza, enough to fill the pod!
In the Our Own League fan novels, Superboy loves peanut butter, eating it straight from the jar. He's also fond anything passion fruit-flavored, because one scientist who helped create him invoked Tastes Like Friendship with passion fruit jellies when he first broke out of his containment pod.
In the works of A.A. Pessimal, the canonical association of Dwarfs with their unique take on bread - and rat-meat - is continued throughout. In Gap Year Adventures, a group of Dwarfs trying their luck in Cenotia complain of the privations of being in a country that considers rat to be a ritually unclean animal and therefore does not sell it in its kosher butchers. All they have is this preserved pig meat we got in Ankh-Morpork as iron rations before we took ship, miss, and they don't like that at all! Their Rimwards Howondalandian hostess has also been suffering in Cenotia for lack of a decent bacon sandwich. She explains their farm has a rat problem in the granaries. Agreement is swiftly made. In keeping with the Up to Eleven treatment of a Fantasy Counterpart Culture, Rimwards Howondalandian characters on the Disc are charcterised by an obsessive craving for things like braaivleiss, bobotie, biltong and melktert. Followed by rooibuis tea.
In The Symphony Verse, Blaine loves chicken, to the point where his friends bring him chicken when he's sad even if it's not dinnertime, simply because it cheers him up.
The boys of Dalton Academy in Dalton are absolutely crazy about Kurt's cookies. Especially Windsor boys, but effective to Stuarts as well. Kurt has no idea why, stating that his cookies are normal, it's just that the people who eat them are off their rockers.
Hetalia: Axis Powers fanfic Gankona, Unnachgiebig, Unità: Italy and pasta. And pizza. And gelato. Germany knew this and made these three foods for Italy when he came over to make him happy. Japan was not thrilled upon finding out. Japan also knew this and had Italy try hijiki and dried shiitake mushroom spaghetti, and Italylover of all kinds of pastaenjoyed it. Germany was not thrilled upon finding out.
The Velociraptors really, really love Oreos. In fact, Barry uses them to lure the girls into their trailer. Blue actually takes ten minutes to savor one, and not one but two Oreos are used to motivate her into trying to solve the intelligence puzzle.
Blue can tell the difference between regular Oreos and double-stuffed Oreos. She prefers the latter. Do not ever try to trick her, as the worker in the above Noodle Incident presumably discovered the consequences. Owen has a minor Oh, Crap! moment when thinking about what would happen if Blue found out about Oreo Thins, reasoning they would have to evacuate the island again.
At one point, Rexy was grooming Blue by licking her, and accidentally took Blue's Oreo. Blue decides to leap into Rexy's mouth to get the Oreo back. Rexy is so startled that she immediately spits out the raptor and looks at Tim, hoping he knows what the heck is going on. Blue got the Oreo back.
Charlie had a fondness for Cheetos. Echo shares this, but especially loves the Cheetos Puffs.
Page Turner has a "Trademark Favorite Flavor" - she likes her food spicy, having been mentioned as freaking other ponies out by snacking on jalapeños, has eaten and enjoyed red habaneros, and is looking forward to trying hotter peppers like Phantom Peppers (AKA Bhut jolokia, the Ghost peppers) and Dragon's Breath (at the time of writing, the hottest pepper on record). It is later revealed that to Changelings, anger has a "spicy" flavor to it. And since she feeds off Night Blade's anger mixed with love, Page has developed a taste for that spicy flavor.
Following common fanon, Celestia loves cake, and she often gets teased for being absolutely obsessed with it. However, at one point she wins a rather sizable bet with Luna simply by taking a tour of a cake factory and not eating any.
Luna is known for loving candy, especially chocolate. In one loop, Nyx (Luna's Enemy Without) manages to redeem her from Nightmare Moon simply by showing her all the great new candy that has been invented in the thousand years she's been gone. In another loop, where Luna is Awake, she returns from her exile and claims she has come in revenge for Pinkie Pie stealing all her candy. Celestia (who is not Awake) is stunned.
This Bites!: The SI character Jeremiah Cross has a low key love for lobster and gorges on it whenever it is available. Sanji, however, was surprised by just how much Cross liked it. Likely Cross did not say anything because one, it is expensive and would give Nami a conniption and two, he is usually too busy being the Straw Hats' third mate, PR guy, tactician and communications officers to think much about food.
In Cori Falls' works, Jessie is insanely fond of French Toast to the point where James can soften her up in her worst moods just by preparing it. She also loves strawberry cheesecake. James is partial to Belgian waffles, Gary likes custard dishes. Meowth's love of fish is merely Stock Animal Diet at work. On the "villains" side, Tracey favors Mountain Dew and pretty much every junk food there is, while Ash is obsessed with cheeseburgers.
One of Yoshizilla Rhedosaurus' infamous Long Runner fics goes by the name of Meloetta's Icing Fetish. The title says it all, really. She specifically likes vanilla icing.
Stephen Ratliff's Marissa Picard, the youngest person to become Captain of the Enterprise (at age 9!) loves everything strawberry flavored. Jelly, ice cream, sodas, anything. She is particularly fond of strawberry juice.
In Bait and Switch (STO) Captain Kanril Eleya loves jumja sticks, a Bajoran sweet that resembles a large lollypop. In chapter three she makes a point of bringing a large takeout box of cooked, not replicated, jumja sticks back to her ship with her. Few chapters go by without at least a mention of them.
Sakuya Izayoi Gives You Advice And Dabs: As in canon (and mythology), the kappa Nitori Kawashiro is fond of cucumbers, and the DLC story centers around an encounter with her where she will give advice in exchange for the vegetables you happened to have on hand.