When it's time to bake big — anything from a 12-inch birthday cake to a day of Christmas cookies to a full wedding cake — prepartion and planning will make the day successful and retain your sanity.
The plan
First, know what you want to bake ahead of time and what recipes you'll use. Spend a day or a week perusing cookbooks, magazines and the Internet for new recipes. This is is almost as good as eating (the best part of baking, of course), and with much less work.
After selecting what you'll make, bookmark all the recipes, and set aside the books or magazines. Then make a grocery list. Don't assume you have six pounds of powdered sugar in the cabinets, either, double check. Check everything, including salt and baking powder. Then buy extra in case of accidents; if you need a dozen eggs, buy the carton of eighteen. The only bigger waste of time than running to the store because you don't have any more cake flour is running to the store because you had just enough cake flour, but the cake didn't cook in the center and now you need more.
Shop early: if the grocery store has run out of sugar or flour, you'll have time for another shopping trip.
Allow yourself enough time to bake too. After five cakes or batches of cookies, my eyes cross and my knees give out, and that doesn't include decorating time. Something's probably caught on fire by then too. For the last wedding cake, all the cakes were baked on a Saturday, and the icings and fillings made the next day. The cakes were filled, iced, wrapped and frozen by Sunday night. Covering the cakes in fondant required about two hours, but making decorations required days.
The prepartion
Pre-measuring and lining your pans the night or day before is the single biggest help you can give yourself. It's like you are your own sous chef. For five cakes, it took me about an hour to measure and label bowls of dry ingredients and line the cake pans and cupcake tins. Each cake needed two bowls: one for flour, spices, and leavening, and one for sugar. Each bowl was labelled.
I pulled all the butter into the refrigerator from the freezer. With more measuring cups, the wet ingredients would have been pre-measured too.
Mixing was a breeze, and there was even time to really clean the mixer, tools, and counters between each cake. My eyes were still crossed by the end of the day, but it was much less stressful. And there were no fires.