Losing Buckets when making cake

I go to make cake and after I did, the buckets were gone!

What I expected to happen was...:
I thought that after I made cake, I would get empty buckets back. Not what happened.

What actually happened was...:
After I made the cake, the buckets were gone. It's a waste of iron in a way, so cakes are REALLY costly to make if the buckets disappear.

Steps to Reproduce:
1. Take what you need to make a cake.
2. Make cake at crafting table.
3. Be sad that you lost 3 buckets.