S.,
Is it a healthy snack or a dessert? Many people serve dessert for snack, but I try not to.
What age are they? Are they old enough to eat carrots like real bunnies do?
My daughter's preschool class always loves carrots with the tops left ON. They feel more like real bunnies. I wash and skin them first, then lay them on a table family style on top of napkins. They are instructed to only touch what they are going to eat, and not to take one if they know they are not going to eat it. If they are unsure, they can take one to try, since trying a food is always encouraged. But they can't take it to join in the fun then not even taste it - that's wasting. So, to have fun, they have to try a healthy food! Even kids who wouldn't otherwise eat a carrot like to join in the fun. Great fun way to get they to eat something other than sugar, sugar, sugar. Many of the kids eat more than one. Organic are sweeter than conventional. Get at Whole Foods, or perhaps regular store organic section.
You could also put out nice fresh crunchy lettuce like romaine, but again a choking hazard for young ones.
They could also cut bread with an easter/spring cookie cutter shapes like bunny or butterfly and spread something on it. My daughter likes avocado or guacamole. They sell a "Sunbutter" seseame seed spread that doesn't violate any "no nut or peanut" rules. Or just eat with butter or plain. Perhaps decorate the bunny with a raisin eye or a marshmallow tail.
Have fun and Good luck!