Tsubaki-mochi (a rice cake stuffed with sweet bean paste and coated with camellia leaves) (椿餅)
Tsubaki-mochi is a rice cake sweets eaten as a light meal in the Heian period.
Sweets in the Heian period were mostly fried confectioneries called togashi or karagashi (Chinese sweets) came from China. The style that dumplings wrapped with plant leaves like Sakuramochi (rice cake with bean jam wrapped in a preserved cherry leaf) is uncommon and there is an opinion that Tsubaki-mochi is unique to Japan, but this is not certain. If we stick to this theory, this Tsubaki-mochi is the origin of Japanese confectionery.
According to the description in Kakai-sho Commentary, Tsubaki-mochi was something like a dumpling made from mochi-ko (rice cake flour, present-day domyojiko [dried and granulated glutinous rice flour]) that was made by grinding dried glutinous rice with a mill-stone, kneaded with amazura (traditional sweetener commonly used in the past), and wrapped with camellia leaves.
Tsubaki-mochi was not eaten as a light meal like present-day sweets, but it was distributed to participants to big events such as kemari (a game played by aristocrats in the Heian period) at noblemen's residences.
Young people are eating confectionery like a Tsubai-mochi, a pear and a mandarin orange mixed on the lid of a bamboo basket, frolicking.' (Wakana [Young green] chapter of The Tale of Genji) vol.1.