What's a great dessert to bring to a potluck?

  1. It is critical that I make a great impression
  2. There will be no heating elements of any kind where I'm going and it's a bit of a drive.
  3. I will be going directly from work to the potluck so I'll need to be able to make this dish the night before. I can store it in the refrigerator at work.

I want something surprisingly good or a solid old standby. It doesn't have to be elegant or healthful. I usually bring a bottle of wine but want to mix it up a bit. I would prefer it not to be cookies or cakes as many people are already bringing those. I do not want to construct a sweet "charcuterie" board because those are everywhere and often disappointing and I think taking cheese from my very cold work refrigerator to my warm car will create sweaty cheese and that's not the look I'm going for.