Love the challenge.
After reading the documentation and the fact that you could send in multiple candies in one request I started to go down that root. I then realised that meant the JSON parsing would be more involved, so switched to sending 5 requests and built quite a tidy solution (well at least I think so!)
Let us all hope that they didn't really consume that many calories!!!!
Edit - I should add that I assumed it was a typo on the fireballs and just replace it in the text input rather than adding a formula
Double Edit - Also turns out you should read the text in workflow as well, as this tells you to do it in one call and not multiple, shame on me!