so why not making one, which does not require any filling...smart, isn't it...???
baking an advent calendar seems to be the solution.
...if you choose a gingerbread dough, you can't do anything wrong...gingerbread cookies lasts long enough, you can easily stamp the cookies or you decorate them with icing.
you can find a very simply and really delicious recipe here
...it is meant for thermomixes, but if you are using any other strong blender, you shoud be fine, too.