In "Making a 3D cake at home", I went through the basics of taking a boxed cake mix and basic cake pans and building them into a wonderful character or object of your choosing. It usually takes 2 boxed cake mixes to accomplish the scale of cake that can reasonably feed a crowd of people. Most box cake mixes turn out a cake that is soft, moist and easily can crumble and fall apart, which makes is difficult to manage when manipulating into your shape. Taking out the fat from the egg yolks added and only adding egg whites makes the cake more spongy, and much easier to handle when cutting and standing up on it side. It gives the cake the strength it needs to stand up to a lot of icing as well. I love the texture of the cake that results from doing this. I also substitute milk for the water, to add a little more moisture. While building the cake, my daughter and I eat every leftover corner or cutout left behind, because it is so good. Using a good serrated knife, or bread knife when cutting the cake helps to keep from tearing or crumbling the cake. Once you have cooled your cake completely and cut your round cakes into halves, (I cut 2 round cakes into halves) you can begin to assemble them on a prepared cardboard cake board.
The shape of the object you are building will determine the way you place your cake pieces on the board. I will use the dinosaur for my example. I placed the cut round halves with cut side to board, using 3 halves side by side for thickness. The halves will stand well untill you get everything arranged to the shape you want them, then you can use icing to glue them together and crumb coat your cake. I then take the last half of the round cake, cut it in half and stand these two pieces up on their side on the cake board for the head, placing it in on the front side of the other 3 half rounds. For the tail, I cut the last round cake into a half moon shape and place it behind the rounds. You can curve it whichever way you want. For the legs, I made 4 egg shapes, using the Wilton egg shaped pan, which are perfect for the legs. Place these to each side. You can secure these with small wooden dowel rods, or just glue on with icing. Stand back and look at your shape, tweak where you need to. I curved my dinosaur a little on the board. When you get everything arranged into the shape you want, go ahead and place buttercream icing between pieces to stick them together and gently ice over all the pieces for a crumb coat. This prevents excess crumbs on your final icing.
Icing the cake, like I said is the most time consuming part of the process. I use buttercream icing from a basic recipe. You will need to double the recipe for enough icing to fill in your cake. A wonderful basic buttercream icing recipe is as follows.
1/2 cup butter
1/2 cup shortening
4 cups powder sugar
2-3 tbsp. milk
1 tsp. vanilla flavoring
I use gel coloring to color the icing. I usually separate it into separate bowls and color it, using a large part for the body and smaller portions for shading and details on the form ie., eyes, claws, spiney forms on dinosaur. I used green for the large portion of the body, a shade darker to enhance around the legs, and create the spines on the back and tail, black for the claws, white for the eyes and teeth. I used just a plain small round tip for the small details. It is necessary to fill in the spaces between the head and body, around the legs and between the tail and body, building with the icing with the star tip to get the full shape you want. Looking a picture of your object is a big help with enhancing the coloring. Embellishments with candies and chocolated cut to shapes is another great idea. I put small chocolate chips in the eyes. You can get as extravagant is you like. The options are endless. After your first one, a basic sheet cake just will not do. It is a lot of fun and your kids will love getting into the decorating. The hard part is watching it get devoured at the party!