I vote for SOUP!!!!!
I like the idea of including other departments. I used to have Baked Potato sales in a facility I worked in. I also had the advantage of working with the Dietary Dept. I had a resident at the "cash register" and a "town crier" who reminded staff of the upcoming sale. I foubnd it was a huge hit for residants and staff and our Resident Council Fund reaped the benefits!!