Sea-salt ice cream

Sea-salt ice cream is an ice cream type found in Twilight Town and Hollow Bastion, created by Scrooge McDuck. The ice cream's flavor mixes both a salty taste with a sweet taste as well. Ansem the Wise was very fond of this ice cream, and often ate it while conversing with King Mickey, and later used it as the password for his computer in the Old Mansion.

Hayner, Pence, and Olette also enjoyed this ice cream. When Roxas first saw them, Axel assumed he also wanted some sea-salt ice cream. Roxas took a liking to it, but Axel did not enjoy it.

Riku left a sea-salt ice cream with a picture of Roxas and the gang from the Simulated Twilight Town as clues for Sora, Donald, and Goofy.

When Sora arrives in Hollow Bastion, he sees Scrooge McDuck, who is trying to recreate the flavor for sea-salt ice cream. Through subsequent visits as the storyline advances, Scrooge comes closer to inventing the flavor.

In one of Roxas' flashbacks, Axel offers him a stick of sea-salt ice cream before their parting. A droplet can be seen falling to the ground, though it is unknown whether the droplet is Axel's tear or just melted ice cream.

In the KH2 manga, Roxas falls off the Clock Tower while trying to catch his ice cream that was sliding off of the stick.

Links
A recipe for sea-salt ice-cream on RecipeZaar