Most people can remember around seven different items in their short term memory. That is probably not going to be enough to win this tough test of Easter recall.
Get a large tray and place on it around 20 small Easter themed items. You might use different color eggs, different types of candy or chocolates, a spring flower, an Easter card, or a small stuffed bunny. What you use is up to you, just keep it within the Easter theme. Once you have your tray set and are ready to play bring it out to the party and place it where it is convenient for the guests to study the items(but no touching). Give them around 15 minutes to take inventory then remove the tray. Pass out pens and paper and give the players five minutes to write down as many of the items as they can. The person with the most correct answers is the winner and gets all of the contents of the tray as a prize.