Also try Rose Levy's White Velvet Butter Cake. It is excellent! It is very similar to the Cooks Illustrated one that you had problems with. I think the only changes are in the flour and sugar measurements and maybe the eggs. Also when baking a recipe in different size pans you sometimes need to adjust the baking powder levels. In the back of Rose's book she give you the recipe measurements for different size pans with this recipe and a few others.