My friend and I made this cake for my daughter's third birthday. I used the Wilton Castle box set that was showcased in their 2009 Yearbook. We made it kind of like a pop-up book. You can use the 2-mix book tin Wilton has or just use a regular rectangular pan and cut the cake to look like an open book. That's what we did. It was really fun and we got a lot of compliments on it.