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 buttercream. Its a simple two layer sheet cake, decorations made from cake and buttercream on top. (large sea shells made of the same cake). The cake looks normal in texture like every other cake, but feels, and tastes much moister. How do I know if a cake is too moist to told up to a layering and decorating?