Santa's Workshop?

That's an old item, not from this season. Santa's workshop seems to be a building from a previous holiday event.

Look in amongst your commercial buildings, if you can see that cane, you may well have the shop already. It's not currently working and hasn't been doing so for at least a couple of years.

Neither has the Chocolate Factory for that matter.

Same as the Chocolate Factory: they're apparently useless after the season when they were first introduced.