Wheel Cake

The wheel cake comes from the Japanese imagawayaki, a molded batter cake that entered Taiwan during the period of Japanese rule and was localized into a beloved street snack. Taiwanese vendors kept the dimpled cast-iron griddle and the two-halves-joined method but multiplied the fillings far beyond the Japanese red-bean standard, adding custard cream, peanut, taro and the distinctly Taiwanese savory dried-radish filling. It picked up several names across the island — wheel cake for its shape, red bean cake for its most common filling, and taiko cake in the south after the Japanese drum. It is a generic street format with no single founding shop, sold from carts and small storefronts.

The shell is soft and spongy like a thin pancake, lightly browned and faintly sweet, with just enough body to hold a generous, hot filling. Bite in and red bean spills out — coarse, sweet, a little earthy — or custard runs thick and warm, or salted radish answers with a savory, slightly crunchy bite against the sweet crust. Eaten fresh off the griddle, the outside is tender and the center steams.

The mold does the shaping. A loose, pourable batter — flour, egg, sugar, milk and a little leavening — is poured into the heated, oiled cast-iron cups; the leavening and the steam from the batter make it rise into a domed cake against the hot metal, browning where it touches through the Maillard reaction. Filling is dropped onto a half that has just set on the surface but is still wet on top, then a second batter-filled cup is inverted and pressed on so the two raw faces fuse as they finish cooking, sealing the filling inside. Timing is everything: pour, fill and join within a short window, or the halves will not bond.