Mall is also connected to the hotel so you have an abundance of top notch food choices from a high end japanese restaurant to castella cakes, coffee / ramen shops and Din Tai Fung all just below the hotel. (kayak.co.uk)
Pull it back out and trim off the edges (traditionally castella is served with the sides cut off but showing the dark brown top and bottom. (eatthelove.com)
It's called castella (kasutera) and its lovely. (eatthelove.com)