A big ball of cake filled with candy?! What the hell else could this be but a PIÑATA CAKE! It's a cake with more goodies inside of it. Wouldn't this look fab on a sweets table (and like tons of work went into it)? It doesn't even seem that hard to make since you bake it before you cut it and fill it up.
You'll need to bake the cake in an oven-safe bowl, carve it up as shown, fill it with goodies, reassemble, and cover with frosting to seal. There are more detailed directions and more photos over at A Subtle Revelry. Check it out and then you MUST share if you end up making this.