As @DLgal said, the official times are 10am onward. We were there around 11 on a Saturday and they said they only had one tray of the gingerbread men left, which was ok by us (tree nut allergy), but then 5 min later they had a whole new cart and people were buying them in multiples. It’s like printing money. So my advice if there is something you really want: chill and wait.
FWIW the GCH hot chocolate was one of the best I have had, and I’m not a sweets person.