I don't even know where to begin. I have multiple questions and concerns. Please bare with me. I'm making three cakes for my daughters' birthday party this weekend. All three will be double layered, decorated with rose swirls. This is my first time making a double layered cake or working with piping. The size pans I purchased are 6x3 (smash cake), 8x3, and 10x3. I'm planning on two being chocolate and one vanilla. I plan on using box cake mixes, and I'm worried about them falling apart. I'm going to freeze them the night before I decorate. Is any brand better for working with layering? Also, how many cups of batter should go in each size pan? Is buttercream my only option for making rose swirls? I tried a half shortening/ butter recipe that was petty gross. I plan on trying a new recipe that is something like 1 cup butter, 3-4 cups powdered sugar, 1tsp vanilla, 1-3tbs milk or cream. Will this hold up? The cakes will be inside besides the 5 minute car ride to the party location. Does anyone have a good icing/ frosting recipe that would work well with what I'm trying to do? The cakes are for children mostly so I would like to avoid a really sugary frosting. I also found a cream cheese buttercream I thought about using for one of the chocolate cakes. Will cream cheese pipe well and hold up? I'm thinking I bit off more than I can chew, but it's too late to turn back now. Any tips/ answers/ suggestions are very much appreciated!!