The desserts (including cake) at Disney's Signature Dining restaurants are in the $15-$17 range. CBS is pricing their desserts at a 40% premium above Disney's signature restaurants. I understand that the products are different, but that is still insane. I am a person who will drop $150 on myself to eat dinner at Topolino's and I LOVE just about any kind of cake, but even I have a limit and CBS has definitely exceeded it. There is other dessert/cafe/restaurant offerings available that are almost half the price. If this were the only option, then I can see where they could get away with $20+ for a slice of cake. Unfortunately, there are other dessert/cafe offerings on the property that are substantially cheaper. Even the "specialty cakes" that you can order at the restaurants are "only" $39 and that's for a whole cake.
I'll be staying at the BW in December and I was looking forward to this restaurant. Alas, I will simply enjoy the free aromas as I walk by.