It's baked in individual maple-leaf-shaped molds because Miyajima's Momijidani ("Maple Valley") park was already famous for its autumn leaves before the cake existed, and confectioners cashed in on the association.
A castella-style sponge batter is baked in a small maple-leaf iron mold and filled with sweet red bean paste (or, in modern versions, custard, chocolate or cheese), sold warm from stalls along Miyajima's shopping street.
Takoyaki (Octopus Balls)
Yakitori (Skewered Chicken)
Sapporo Miso Ramen