Most of the work of making a wedding cake isn't in the artistic presentation, but in repeatedly mixing batter, filling cake pans, and transferring giant slabs of cake without creating fault lines. Monotonous as it can be, there are a few tricks to making the final product turn out as you would like. Here are some pictures of the process:

Both the metal cone in the center and the strip of wet fabric around the pan help to ensure more even baking. The plywood on the left was covered in foil to make a tray for the cake. My uncle cut this one for me; he had also cut the one I used for my sister's wedding cake.

In order to get the full 2" height of the pan, the cake batter needs to fill 2/3 to 3/4 of the pan. All the cake that rises above the pan gets cut off to even with the edge of the pan.

That way, once the cake is flipped onto the rack, it lies perfectly flat, cooling and waiting to be cut in half lengthwise to make two 1" layers.
The filling for the chocolate cake is chocolate mousse. I've used this recipe several times, and I like the rich chocolate flavor and the consistency. It's pretty easy, particularly since I used the grater attachment on a food processor to "chop" the chocolate.
Chocolate Mousse
2 cups heavy cream
3 oz unsweetened chocolate
1/2 cup sugar
Heat 1/2 cup cream in saucepan over medium heat, until just about to boil. Finely chop the chocolate and place in bowl. Pour hot cream over chocolate, stir once, cover, and set aside. Whip remaining cream and sugar in the other bowl until they form soft peaks. Stir the chocolate mixture until all is melted and well incorporated, then fold in the cream. Chill for at least two hours.
The first time I made this recipe, I was worried that it would be no better than than the chocolate Redi-Whip, but as it chills, it thickens and even seems to get richer. The bowl on the left is a fresh batch, not yet chilled, and the bowl on the right is one that had chilled overnight. I've only used it thus far as a cake filling, but perhaps someday I'll serve it as a dessert in its own right, in little chocolate bowls or martini glasses, with raspberries and chocolate shavings as a garnish.

But, back to the cake. To fill the layers, pipe a barrier of frosting around the edge of the cake layer. This keeps the mousse (or raspberry, or pudding, or whatever filling you like) from squishing out when you stack the layers. Spread the mousse with a spatula or the back of the spoon. One recipe of the chocolate mousse filled each layer of this 12" square cake, so I needed three batches total.
So, that's the basic idea, and like I wrote above, the whole process is a repetition of these steps- all day long. And, in the end, you get three square cakes, filled and ready to frost. Notice the huge bowls of frosting on the right; it took all of that to frost those three cakes. Here's what they looked like naked:

By midnight the night before the wedding, the three cakes were frosted, waiting to be smoothed, transported, stacked , and decorated. And yes, I stored them covered and in the refrigerator, not out on the kitchen table.
