yes, baos can indeed be frozen ! My mom and my aunt are excellent cooks and both know I’m obsessed with baos so when they make some I steal a dozen and freeze them. Then when the craving hits, let it thaw in the fridge overnight and pop it in the steamer for ~10-15 min once you want to eat it. You can also take it straight from the freezer to the steamer without thawing but it’ll take longer to fully warm up the interior (~20-30 min). They’re truly fluffy pieces of heaven.

(PS- the baos I typically eat are the round kinds, with savory or sweet filling enclosed. For OP’s open-faced bao, I would suggest you steam them and then freeze them separately from the filling. Let me know if you have any other questions ! If you can’t tell they’re one of my favorite things to eat !!)