Cake is tasty, pre-divided cake is convenient, and food is often better with a combination of textures and flavors. And so we have frosted cupcakes:
While these look good, they're bad food. The problem is they're very hard to eat while getting a combination of cake and frosting in each bite. Vertical slice bites are impractical for people with non-pythonic jaws, and it's hard to alternate without undermining the frosting. Also the frosting needs to be quite firm to stand up to this stacking, limiting texture options.
You can make a jaw-compatible cupcake by restraining your frosting application to a thin layer, but this is stoichiometrically unsound.
Instead of putting goop on top of the cupcake, it should go in the middle. Here's one I made, piping plum into the center of a chocolate cupcake:
Each bite is balanced, you have full artistic freedom when it comes to texture, and no one gets trismus. You can even put a (thin!) layer of frosting on top if you're using a subtle flavor, the filling injection wounds aren't appetizing, or just two components wouldn't sufficiently impress your guests.
Food should be optimized for eating.