Some people do have cinnamon allergies, I suppose.
I can’t vouch for what this would taste like. I would guess this intends to call for powdered sassafras root, a flavoring agent used in tea and in traditional root beer, and not powdered sassafras leaves, better known as filé powder for gumbo filé. So that part is pretty familiar to most of us.
But cranesbill, as it happens, is a variety of geranium. And I rarely do that much culinary investigation of the flower shop.
From a box sold in Chicago, Illinois.
3/4 cup powdered sassafras
1/4 cup powdered cranesbill
Blend the two herbs.