A sweet and sour pastry made from red berries (hawthorn) and cane sugar. Song Xia gave it the name sour cake to keep its ingredients secret. It has a translucent quality resembling gemstone or crystal, with wavy edges and a simple flower pattern stamped on top. The flavor profile is intense sourness first, followed by sweetness, with a lingering sour aftertaste. It was solidified by resting in a well overnight. Song Xia planned to sell it in the county town.
