Make Ahead
Decorated cupcakes can be made ahead of time. Prepare as directed, except do not top with marshmallows and graham pieces. Refrigerate up to 8 hours. Top with marshmallows and graham pieces just before serving.
Variation
If you don't have 24 jelly jars, you can fill and top the split cupcakes on a platter instead.
How to Store
Keep refrigerated.