This one isn't so much a decorative cake as a YUMMY cake.
You take a normal white cake mix and all the stuff it says for it then add 3 tablespoons of any flavor jello mix. Then cook it like normal. For the frosting it's 1/3 cup butter 3.5 cups powdered sugar 3-4 tablespoons milk and the rest of the jello mix (smaller box of jello, makes 4 servings) then you mix that up and it makes frosting.
It's FANTASTIC. Really tasty moist cake and the frosting is totally different from any I've had. VERY flavorful and sweet but not crazy sweet like the buttercream I've been making. Delish!
ETA: I just ate a slice (I had only had a bite before) and it's REALLY sweet. It's good, but very, very sweet. The frosting is also very different from buttercream, it's almost sticky. I couldn't eat all the frosting, but then I never can.