Since this is a kiddie project, there really are no rules. I will give you what I used to "create" their masterpieces but you can adapt this any and every way possible.
1 box white yellow cake mix(I wanted Halloween Funfetti, but they were out)
1/3 cup veggie oil
1/4 cup water
1 jar of Halloween sprinkles
1 jar cream cheese frosting
Preheat oven to 350'
Mix together dry cake mix, oil, eggs and water, then add whatever amount of sprinkles you want.
I normally use a round TBSP to place on cookie sheet, but you can also use a round TSP to make them bite size and get more out of it. Bake 8-9 minutes
Top with the frosting and then line the kiddies up and let them decorate these however they'd like! the kids loved doing this and enjoyed eating them even more!