In order to make a cake easier to ice, especially if it is a very crumbly cake, you can place it in your freezer after you bake it. Leave it in the freezer over night. When you go to ice it the next morning it is easier to ice because you won’t get as many crumbs in the icing and you don’t have to put on a crumb coat first. Once you're done icing it, just leave it out for a few hours and it will thaw out. I do this with almost every cake I bake and it does not effect the taste or texture.