Yummy Sweets! A topic nearest my heart..
Have you thought of an outer layer of meringue? It seems like it would offer protection in many ways: withstand direct sunlight, hold its form, and even keep the center moist and grit free.
Here... Enjoy a cupcake from Sugar Bliss
"The truth is incontrovertible.
Malice may attack it,
ignorance may deride it,
but in the end, there it is."