Sand cookies fail for not being made from sand. You could always wander over and stash them in the platinum crate, left of the former platinum mine. Stick them in picinic baskets and leave them at the doorsteps of the occupied guild houses around town. Fill up any empty containers you find that are not crafting equipment. Are there really that many people making sand cookies? I've never made even one with my 38 cooking and 44 baking.
Put up a notice that you cannot accept them as donations. Give them to alts that get out of town once in a while instead of making the trip yourself. Make a special dozen free sand cookies with every purchase