I agree that I think she/they just want to make sure that they get the "best " cake possible ... which in their opinion is scratch not box.
I 100% understand food allergies, my dad's side of the family (including myself) are all ... "sensitive" to onions. I don't know that I would say allergic only b/c I think of allergies as being more physical (swelling, suffocating, hives, etc.) we have alot of sneezing, coughing, sinus pressure, watery eyes, mild vomiting ...
I don't say "i can't eat mexican food" I say "i can't eat onions" 2 completely different things!
I was texting back & forth with the B2B the other night & asked her to be more specific but she just danced around it & was really really vague. I told her that I was researching it online & consulting with fellow cakerators to try & come up with a safe recipe.
Her final text to me was :
B2B ~ Wow, thnx. Don't stress over it though! Just as long as the cake taste awesome! I'll just tell her to take a benedryl before eating it .. lol