My plan to adapt the concept of the mix-and-match animal parts book into a 3-dimensional cake was to build the cake around a central pole, so that each tier would be able to rotate independently of the others. The first tier was the feet, the second tier the body, and the third tier the head. Because I was planning to put all kinds of decorative schmutz onto and into these cakes and because I wanted to have just a basic chocolate cake section for the one-year-old birthday boy to smush, I also made a hat for the fourth tier, which frankly didn't really add a whole lot, visually or conceptually speaking.
Each tier was divided into three sections, each decorated like a different animal. That way, you could line all the sides up so that the three animals appeared in their entirety on the three sides of the cake, or you could rotate the sections relative to one another so that, for, instance, each side of the cake would show the feet of one animal, the body of another, and the head of the third. I also wanted to experiment with different decorating and texturing techniques, so rather than decorating in the usual way with only fondant and frosting and food coloring, I decided to enhance the primary texture of each animal with a different food product and then also coordinate the flavor of the cake within to the decor on the facade of the cake. My animal / decoration / flavor combinations were:
Side #1: Monkey / Nuts / Hazelnut Chocolate Cake
The monkey side of the cake was made of chocolate cake with hazelnut paste added to the batter, with nuts of various types and textures applied to the outside to create the appearance of matted monkey fur.
Side #2: Bird / Candied Citrus Peel / Chocolate Orange Zest Cake
The bird was chocolate cake with orange zest added to the batter, with candied lemon, orange, and grapefruit peel feathers.
Side #3: Alligator / Sugared Mint Leaves / Mint Chocolate Chip Cake
The alligator was chocolate cake with mint chocolate chips mixed in, with sugar-coated mint leaves for the textured skin.
The first thing I needed was a central pole for my cakes to rotate around. I started with a heavy circular wooden base with a 3/4" threaded rod screwed into a phalange in the center. To support the cakes, I got four plexiglass circles with holes drilled in the middle with acrylic tubes the height of the tiers glued around the holes. So that we would be able to turn the tiers without touching the cakes, I glued little plexiglass circles onto the edges of the bigger circles to use as handles. To support these plexi cake bases, I used big nuts and fender washers, screwed onto the central threaded rod. Each tier required three nuts and a fender washer. The nuts were just the right size to fit inside the acrylic tube while the fender washers were big enough for the plexi bases to rest on. To assemble, I started with one nut, then a fender washer, then another nut pinching the fender washer in between. Then one more nut, positioned so that the distance from the top of the fender washer to the top of the nut was the same as the height of the tier. That way, when I slipped the plexi plate and acrylic tube over the nuts, the plate rested on the fender washer and the nuts at the top and bottom kept the whole piece stable. Then repeat the whole operation for each successive tier. I did a dry run putting this whole assembly together without cake to make sure it would work the way it did in my head before I started working on any of the edible cake components. When I reassembled it later with the cakes in place, I also sprayed the washers with cooking spray as lubricant to counteract the weight of the cakes, which I was afraid would hinder the rotation.
Before I started on the cakes themselves, there was lot of advance work to do:
Sugared mint leaves:
These were easy to make, if a bit gooey and tedious. Fortunately, my sister had a big mint plant in her back yard, so I had ready access to a virtually infinite supply of mint leaves. To sugar them, I dipped each leaf one at a time in egg white, then in granulated sugar and put them on wax paper to dry. I have since realized that I could probably have gotten a nicer result had I rubbed on the egg white with my fingers in a thinner layer and then sifted the sugar overtop. As it was, some of my leaves got too much egg white or too much sugar on them and wound up being unusable or just a little lumpy and weird.
Candied citrus peels:
I started with lemon peels, orange peels, and grapefruit peels, so that I would have a variety of sizes and colors to use for my feathers, using a recipe from Jacques Torres. First I cut the fruit into fourths and removed the peels. My mom was in town (she and Dad were both a big help on this cake) so she took the leftover fruit and carefully separated the fruit from the inner membranes to feed to my nephew. I tried to eat some of the grapefruit but Mom shooed me away. Apparently I don't rate as highly as he does. The pieces of peel went into a pot of boiling water three times to blanch some of the bitterness out of them. Then they went into a pot of sugary water to simmer for a couple of hours. Then I pulled them out of the syrup and left them on a wire rack to drain and dry. I had been lead to believe, by Jacques Torres' recipe, that they would dry out in a few hours. As usual, Jacques' recipe didn't work out the way I expected. None of Jacques' recipes that I have ever tried have worked out the way I expected. I left the peels out on the rack overnight, and they were still nowhere near dry. At that point, I became pressed for time, so I had to put them into a warm oven to dry before I could put them on the cake.
Gum paste faces:
To make the snouts of the alligator and the monkey and the beak of the bird protrude appropriately from the cake surface, I made them in advance out of gum paste. As it turned out, I didn't make them quite enough in advance, as the beak wasn't quite fully hard when I went to attach it, but I'll get to that in a little bit. In order to get the shapes I needed, I draped rolled-out sheets of gum paste over forms. In the case of the monkey nose and the alligator snout I was able to find cups lying around the kitchen that were basically the right size and shape. To get the more distinctive shape of the bird's beak, I made my own form out of cardboard. All the forms had to be liberally coated with corn starch before applying the gum paste to insure that the finished pieces would release easily.
When it came time to make the cakes and the frostings, Mom and Dad were invaluable, with Mom doing most of the baking work and Dad doing most of the cleanup. For each tier, we made three two-inch tall cakes - one of each of the three flavors described above. I torted each of the cakes and filled them with chocolate buttercream frosting. Then I cut each of the cakes into thirds and stacked the thirds on top of each other, so that I wound up with three pie wedges per tier, one in each flavor, each about six inches tall. I had to cut a little divot out of the corner of each pie wedge so I could fit them around the central tubes, assembling the pie wedges back into circles. As it turns out, cakes are much flimsier when they're built this way and until I finished carving them and covering them with fondant I was very worried that the three sections of the cakes would flop outwards like the petals of a flower. As I said before, I had conceived of the hat as the smash cake for the birthday boy, so for that one I simply made a basic chocolate cake and didn't have to worry about cutting it into thirds.
Carving was pretty easy, actually, since I was going for sort of puffy cartoony animal shapes. Once I had them covered with fondant, I was able to stick my gum paste beaks and snouts on with royal icing, holding them in place with skewers until the icing dried. Unfortunately the beak wasn't quite dry enough and it sort of sunk over the skewer, so I had to leave the skewer embedded in it and pipe royal icing on top to hide the end of the skewer sticking out.
I added a base layer of royal icing details - feathers and fur and scales - because I didn't trust my textural appliques to provide the level of detail that I was looking for. I also added facial features to the heads, and nipples and belly buttons to the torsos. I wasn't quite sure what to do with the hat, so I just gave it a poorly executed inverted shell border.
Because I was visiting my sister when I made this cake, I didn't have my airbrush with me, so I had to paint the colors on the old fashioned way - with a soft brush and some paste food coloring. I didn't do a very good job - so I wound up with a lot of drips and messy brush marks. I also think I either went too muted with the alligator colors or too bright with the bird colors because they sort of didn't belong in the same world.
I was pleased with the effect of my appliques, though. I did get a little carried away with the alligator. I'm not sure why I put a little flower of mint petals around its belly button (which reptile don't even have, by the way!) My bird wound up looking a bit like it was on drugs, because I gave it big blank staring eyes surrounded by dramatic lemon peel lashes. The monkey was apparently a bit diseased, since its shoulders were bald and red and splotchy. You didn't really expect me to successfully make cute little children's book animals, did you?
The board had to be pretty big relative to the cake in order to make sure that it was stable, but I hadn't given any thought whatsoever to decorating it, so it looked very bare. Mom suggested that we get some rosemary sprigs from the garden to gussy it up a little. I think it helped.
Whatever aesthetic faults the cake may have had, my rotation mechanism worked flawlessly. With that aspect, I really couldn't have been happier. Each tier spun easily and smoothly and yet the cake as a whole still felt rock solid.