Take the foam that will be a substitute for a strawberry mousse and set aside.
Next melt some chocolate and break graham crackers into halves or fourths depending on how big you want the serving to be. Have the littles dip the crackers in chocolate and begin to make boxes with the chocolate as the glue to hold everything together. If you use quarters then it will be a two sided box.
Once the chocolate has set. scoop in the foam left over from the jam. Drizzle more chocolate (and white chocolate just for fun) over the top. Refrigerate and enjoy.