My boss is retiring next month, and my coworkers are having a going-away party for him. Since he’s an accountant, I made an adding machine cake for his farewell party. For those of you who are not familiar with such antiquated pieces of computing technology, an adding machine is just a fancy calculator with a little space for printing out your calculations. I found some pictures online of what an adding machine cake might look like, and then I got to work.
First, I made my homemade fondant (using powdered sugar and glycerin), because fondant needs to set up for 24 hours before you put it on your cake. I couldn’t find my original fondant recipe, so I had to use a new one. If you’re going to make homemade fondant, make sure you get a good recipe that explains things succinctly and in order. I read the recipe through several times, but when I was making the fondant, the recipe was all over the place. I made a much bigger mess than I needed to, and the fondant didn’t turn out anyway. It was way too dry and crumbly. I tried fixing it by kneading in more shortening and zapping it in the microwave for a few seconds, but I kneaded small batches for over an hour just to get enough fondant to do my embellishments. Even though I was able to get a small portion of the homemade fondant to the point that it was usable, I ended up just making a second batch using the marshmallow fondant recipe. I always thought that marshmallow fondant was cheating, but now, I might be inclined to take my judgemental words back. Marshmallow fondant saved my butt– at 11 PM last night, I still couldn’t knead enough crisco into my overly dry fondant to get enough of it to cover my cake. In less than an hour, I had a brand new batch of marshmallow fondant ready to go. The recipe said to let the marshmallow fondant recipe sit overnight, but it was fine after sitting for an hour or so.
After I made my first batch of fondant, I wrapped it up and let it sit overnight. The next day, I made a 13″ x 9″ yellow cake. I cut a few inches off the bottom of the long side and stacked it on top of the remaining piece of cake. I used a butter knife to trim the edges so that the corners were round nicely. Then, I used a butter knife to cut an angle in the short piece to make the section for the adding machine display. I put the cake in the deep freezer to cool completely.
While the cake was cooling, I started fixing my first batch of homemade fondant. I got enough for my adding machine buttons, my adding machine display, and my adding machine tape (the paper!). I used gel food dye to make the colors– my adding machine tape is really white because I used colorless vanilla extract. I think almond extract is disgusting, and I never make fondant with it, even though most recipes call for almond extract. I always stick with vanilla or peppermint extracts. Using regular vailla extract just leaves a little ivory tint to my fondant, so I make sure I use the colorless flavoring if I need perfectly white fondant. To make the buttons, I used a small square cookie cutter. For the black display, I just used a ruler to cut a skinny rectangle in the fondant. For the adding machine tape, I rolled out a flat piece of fondant, Use my ruler to trim it into a rectangle, and then rolled it up. The inner part squeezed out a little bit, so I just worked it into a little bracket that looks like a paper holder.
When I realized that I had been kneading the same batch of fondant for 3+ hours and still could not get a non-crumbling layer to cover my whole cake, I decided to scrap the rest and make a marshmallow fondant. The marshmallow fondant will not be perfectly white. I’m not sure why it turned out slightly ivory in color, but I like the slight color contrast between the base layer and the adding machine tape.
I used a toothpick and cookie decorating icing to draw my numbers on the buttons. If I hadn’t wasted so much time on trying to save my first batch of fondant, I could have done a lot more with the details. That’s the fun of using fondant, afterall.
This cake was very easy to make. If you decide to make one for the accountant, auditor, or math whiz in your life, I highly recommend that you test the fondant out weeks in advance! Fondant keeps really well, so on the off chance that you make a perfect batch during your test run, you can just wrap it up in plastic wrap and store it in a cool spot in an air-tight container.