How about just going with something simple like the "(school name) Annual Auction and Social". That would make it quite clear to everyone as to what the event is and then you can promote the items you have for the auction and what a nice opportunity it is to meet other parents and enjoy a delicious dessert. Maybe do up your flyer to look like an invitation.

The Student Council sells refreshments-sodas and dessert items-and that's usually it. We normally end up running later than we planned because we have so many prizes to call, and this year is shaping up to be the biggest year yet. (Yay!)

Do you have anything else going on at the event besides the auction?

Every year we have a Penny Social in November, a type of silent auction. I remember before I got involved with PTA not knowing what the heck a Penny Social was as the title isn't very descriptive, and besides, back then tickets were a dime not a penny.
In the past few years ticket prices have gone up to a quarter apiece or 5/$1 and this year prices may rise again slightly.
We'd like to rename the event but are stuck on what to call it; one year the president called it the "Fall Fling", but that wasn't any better than the Penny Social. Any ideas? Thanks!