Do it myself!: March 2008

The digger cake was for my nephew's second birthday. I figured that two was old enough that I should make the cake relate to his interests, but young enough that I still had majority creative control.

Testing the mechanism on YouTube
...and digging out the first piece

My nephew loves trucks. Excavators were an early favorite. So when it came time to make his second birthday cake, I thought he'd enjoy a cake with a digger built right in. To amuse myself, I decided to make the cake shaped like a giant face, rising up out of the dirt with the digger coming out of its mouth. I liked the idea of gouging out the cake's cheek with a big metal scoop.

The first order of business was to make the scoop. I purchased some plans from somewhere on the internet and adapted them a bit to suit my own needs. I needed the digger to be able to reach all parts of the cake, so it had to spin 360 degrees and it had to move from the perimeter of the cake to the center.

Basically, the mechanism I came up with consisted of a 1" ID steel tube 4" long, mounted to a heavy wooden base. Nested inside that tube was a length of 1" OD aluminum tube about 1' in height. This inner tube had a notch cut into the top so that the digger arm could slide up and down within it. Then a bolt ran through the top of the tube and through the aluminum bar that formed the main arm of the digger. This arm had a track cut in it so that it could slide in and out, closer to and further from the digger's pivot point. Connected to this digger arm was another handle, connected in turn to the scoop itself, so that it could be used to rotate the scoop up and down.

As soon as my nephew saw the scoop he was determined to master its use, which actually required a fair amount of manual dexterity. Since manual dexterity is not a strong suit of most not-quite-two-year-olds, he had some initial trouble and got very frustrated the first day, but he was determined and within a few days he was using it like a pro. Then I had to reclaim it so that I could actually use it for the cake.

I used chocolate cake, of course, since that way it would look like dirt when we scooped it up. I started with some oval cakes and carved them into a big, sort of cartoonish, oversized face shape. Since it was for a child's birthday party and it was going to be gouged out with a metal scoop I didn't want it to be 100% realistic. That seemed like it would be too macabre for the occasion.

Because I wanted it to be easy to dig, I wanted to ice the cake with standard buttercream, rather than fondant, which I thought would be difficult to tear through with the scoop. So I used a nice thick coating of buttercream icing and smoothed it with a damp paintbrush. For the eyes, I made some little gum paste half spheres and cut out the irises so I'd have somewhere to stick the candles. With those in place, I piped more buttercream on to get the details of the eyelids, lips, and nose.

Then, to make it look like the face was rising up out of the dirt I made a batch of pressed sugar, which is just regular white sugar with a bit of water mixed in thoroughly. It can then be pressed into a mold, or, as in this case, shaped by hand. I used it to build up a hill of sugar around the face. For good measure, I put a few blobs of dirt onto the face itself, as if the face had just risen from the earth and hadn't yet shaken off the detritus.

My next step was to airbrush the face. I started by putting in some blue veins as an undercoat, then built up shades of flesh tone, red, and brown, then some dark purple for shadows. I wasn't altogether happy with how the dirt looked, so I sprinkled on some brown sugar to give it more variety and depth.

I hadn't masked off the gum paste eyeballs, so I had to carefully wash off the airbrush color with a damp paintbrush. For eyebrows and eyelashes I piped on some royal icing detail, then painted in irises, painted the eyebrows and lashes, and painted on some white highlights on the eyes and lips.