I've been asked how to make and stack a wedding cake. Well, here is What I do. This is one of the larger cakes I've made. The base is a 16" square in Chocolate with chocolate ganache, and on it is a 12" square red velvet with cream cheese filling, on that is a 8" faded blue layer, and on the top is a 5" chocolate ganache layer.
To start, do all your prep ahead of time. Here are the cake boards. The bottom is a 1/2 inch piece of plywood covered in contact paper. I use wood for the base because this cake will weigh about 75 pounds by the time I'm done with it. Each layer of cake gets a piece of cardboard under it covered in fancifoil. Regular Foil is ok for small cakes, but tears too easily.
Day 1: Baking day. For a cake this large, I allow the entire day to bake, fill and dirty ice. I started baking these at 8:00 a.m. and finished and went to bed at 10:00 that night. Keep in mind I only have 1 standard kitchen oven and one of each pan size. I have 4 layers of cake in each level. the 16" layer I baked each layer separately to make it easier to move and handle. The red velvet, I baked thicker layers then sliced them in half horizontally to make a total of 4 layers. The layer that fades blue had to be baked 4 different times because each layer is a different color. I cut each layer to about 1" thick. This way the finished cake will have each tier equal heights.
This table is 4 feet wide and 6 feet long. This is a lot of cake...
Here is my ganache. It consists of equal parts (by weight) chocolate chips and cream. Heat cream to almost boiling (don't boil) then pour over room temperature chocolate chips. Let sit for a minute then wisk until it is all incorporated. Chill for several hours before using. Super yummy. You can either us this as is. It looks shiny and soft like below:
Spread that ganache on the cake, inside the buttercream border you piped. Keeping things as level and smooth as possible is important. Repeat this 3 more times until you have your bottom tier done. I used just over 4 pounds of chocolate and almost half a gallon of heavy cream to make enough ganache for this cake. You see why this is going to be heavy?
Do the same with each layer. Here is a picture of the faded blue layer before assembling.
Each layer should be assembled and dirty iced. Put these in the refrigerator overnight. You want to get these cold all the way to the center. It will add stability and allow a smoother buttercream or fondant exterior. Also, do you see the slight bulge on right of the large chocolate layer? The next day when I pulled these out, I could easily trim off anything that wasn't perfectly square and straight. Cold cake is so much easier to handle. If you only chill for an hour or so, the middle won't keep the whole cake cold while you are working with it and it will squish and move while you are working with it. Not much, but it is better to go ahead and chill overnight.
Frost each layer, decorate, insert dowels into each layer to support the tier above it, stack, touch up, and you're done.