Esme found the rabbit toy in the cookie jar today while I was at work. Mark said she came up to him excitedly saying 'cookie rabbit cookie rabbit!' It's been three days, or less. I told Mark that after she goes to sleep tonight I should put him back in there so she has to wonder where he is. And then see how long it takes her to look for him in the original place.
I feel a little evil doing that. But.... I think it is a great idea!