I only make cookies once a year during Christmas for fun and I use the Sally’s baking addiction sugar cookie and royal icing recipe but always have this issue. After baking, the surface of the cookie is kind of flaky and crumbly so then when I do flooding you can see what’s flaked off.

Does anyone have any advice for how to fix this? I’m not sure if it’s an issue with the recipe/my ingredients or how I’m making the dough.

Also, does anyone have tips for how to make white royal icing more white? Mine always dries to be a creamish color.