Building Blocks Cakes This is the first time I have made a decorated cake and it did require some patience. The edges where the cake is cut are difficult to ice, especially since once the cake was cut I did not have room in the freezer for it so it had to chill in the fridge which was probably not as effective. As for the crumb layer--I found that when the crumbs were sticking to the knife badly it worked best to wipe the knife clean and start with fresh icing. I had plenty of icing to work with so don't worry about using up too much when scraping off the knife like this. I ended up needing whole tubes of Betty Crocker gel color for the blue and yellow. For the red I used a whole tube of gel color plus some liquid food coloring I had as well because it didn't seem red enough with just the one tube. The cake fed 24 people--one square piece with marshmallow half each. We all loved it and I am looking forward to gaining more cake-making experience.