I had 10 BtA spirit cakes (from the egg hunt) on one character, to spread about as I needed. I log in after the patch to find they're now BtC, so I cannot move them.
For the suggestions forum, I suggest you become more customer focused.
If you needed to make spirit cakes BtC in order to meet your needs with the new Grog quest, I can understand that. However, you could have expressed your interest in customer concerns by telling people about this change in advance. Better yet, you could have made a duplicate version of the cake and made the new version BtC, leaving the old version alone.
Instead of making a decision that was focused on the customer, you once again chose to take the simple path without regard for the way your customers would be affected.