Hi Everyone.   I am semi new to cake decorating. I have two major orders due today. I am sick and tried a short cut to help me get through this. I used Buttermilk in a box cake mix. I am doing an order for a 1/2 sheet cake. I substituted exact amount of buttermilk for water as suggested. I have never done this before and I feel like the cake is just so moist. It tastes so good. But I am concerned its going to get soggy after a day or two or not be able to handle the...