This article [0] has a pretty good overview of the possible side-effects one can have. The substance toxic to the liver (hepatotoxic) is believed to be coumarin

This article [0] has a pretty good overview of the possible side-effects one can have. The substance toxic to the liver (hepatotoxic) is believed to be coumarin. An article that specifically looks at coumarin in food can be found here. [1] It confirms what the parent comment says. Cassia is also the form commonly used in pastries according to the article. [0] https://doi.org/10.1016/j.clnu.2018.03.013 https://doi.org/10.1016/j.clnu.2018.03.013 [1] https://doi.org/10.1016/j.foodchem.2007.12.068 https://doi.org/10.1016/j.foodchem.2007.12.068