I played Embercaster, followed by Mana biscuit. It triggered, but instead of 3 Mana biscuits, I got 3 CONJURE Mana biscuits.
Sounds like you played Conjure Mana Biscuit. You’ll have to prove otherwise. Post a link to a screenshot or hsreplay surrounded by backquotes `like this`.
I don’t use any recording software. However, it might be possible. Was turn 5, so it would mean I had somehow discounted the conjure by 2 mana.