This is a vintage Japanese sweets mold called "kashigata".
御大師 (odaishi) on sweets mold means a great master of Buddhism especially like "空海 / 弘法大師" (ku-kai / kouboudaishi). He propagated Japanese Buddhism "真言宗" (shingonsyu).
*He is also a great master of calligraphy. "弘法にも筆の誤り" means "Even KouBoudaishi spoiled in writing". This is allegory that even master makes a mistake.
The shape is believed to have originated in the Edo period, and a representation of fertility.
Often made of sakura (cherry wood) and seasoned for about 3 years before carving, kashigata were used to make dried confectionery made of rice flour and sugar called rakugan. Earliest records show that this practice dates back to the mid-17th century. These confections were used as offerings and snacks for celebratory occasions and even unfortunate events. For example when a person died, it was expensive to give flowers or fresh food so, people made these sweets in the form of flowers, fish etc. These items were then placed on the "butsudan" (family shrine found in the house) for the dead person.
Kashigata were also used in the making of wagashi (nama-gashi or freshly made cake and hi-gashi or dried confectionery) for tea ceremonies.
Common kashigata motifs in the Edo era - chrysanthemums, plum blossoms
Meiji Era - spread of western technology - balloons, planes
World War II - national pride heightened - cherry blossoms, battleships - used as gifts for departing troops, ceremonies and commemorative occasions
With the advent of refrigeration, fresh fish replaced rakugan motifs like the sea bream. Sadly today, making offerings for fortunate and unfortunate events is no longer a common practice. This in turn has lessened rakugan demand although they are still found in tea ceremonies and homes. The decrease in kashigata artisans today has made kashigata carving a dying craft making kashigata itself a sought-after collectible.
*You can use this mold as food mold to cook. Please clean thoroughly before using.
*It measures 24.5 cm long x 7.5 cm wide x 4.3 cm tall.