I'll bite! lol There is a crackled sugar cookie recipe and then there is/are recipes for sugar cookie dough that doesn't crack/ or do not have crackle. Don't over mix your dough (in the stand mixer), don't over knead it, don't add a lot of flour when you knead it or roll it out, don't use baking soda or baking powder, don't over mix butter and sugar (it aerates it too much - domed cookies, etc.).
I use a fondant smoother or small spatula and press down lightly on my cookies until I feel a smooth surface. Sometimes I have to do it more than once.
Use room temp ingredients.
Sugar cookie dough recipes: Julia usher, sweetambs, sweetsugarbelle, haniela's, montreal confection. Other than well noted Italian bakers I also like Joanne Chang.