Custom CNC Tiramisu Decoration

My entire life, our family has always owned Basset Hounds. Our latest and greatest model is none other than Dodger (named after the Dodger stadium—we have a tradition of baseball names). She is an icon among our family and friends, having much more influence than could ever be reasonably expected from a (not-so-particularly bright) dog. For Thanksgiving dinner, I was tasked with baking the dessert, and I wanted it to be a show-stopper. I chose to honor my muse with a one-of-a-kind tiramisu.

For the purposes of the CNC Student Design Contest, I'm a student at Rice University.

I used a CNC lasercutter to cut 1/8" acrylic for this project. I then followed my favorite tiramisu recipe from NYT, but added my own spin on the topping—so you'll need extra cocoa powder (preferably a couple different types/shades) and confectioner's sugar. You'll also need one overly-doted basset hound.

I knew I wanted to emulate our adored mascot in some way, but at the beginning, I was not sure how. I then realized I could replicate Dodger's likeness in different shades of cocoa powder on the top of the tiramisu (cocoa powder is the traditional dusting)! The first step of the process was to select the ideal image of our beloved basset—good lighting, her best side, and the perfect expression of disbelief and ennui.

After choosing the perfect photo, the next step was to somehow reduce it to just a few shades. I wasn't sure how to go about this...it wasn't as simple as converting to black and white, but I knew didn't want to be mixing dozens of colors. I wanted blocky colors, similar Obama's 2008 iconic "HOPE" poster. And then it hit me: why not simply do that? I first removed the background from Dodger's portrait and and adjusted the lighting slightly. Then I used obamapostermaker.com (no affiliation) to convert it into a gorgeous 4-color political campaign poster. My phone immediately began ringing with DC area codes showing their support (optional step).

The image returned by the poster generator was a bit rough around the edges. I used Procreate on my iPad to smooth the curves, reduce noise, and make them easier to trace. I then inserted this photo as a canvas in Fusion 360, created a sketch on top of it, and traced it using spline curves. This step was a bit tedious, but it left me with four distinct outlines, one for each color, that would recreate each layer in the image (excluding the background). After finishing the sketch, I exported it as a DXF which could be interpreted by the CNC laser cutter.

This part was pretty straightforward. I cut four templates—one for each color—out of 1/8" acrylic. Since I was cutting out the color (I needed the negative space because this is a stencil), I made sure to also cut out a rectangular outline that would fit over an 11" x 17" baking pan.

Before game day, I did a dry-run of the stencils with all the cocoa powders I could find in the kitchen. I knew the background would be a dusting of confectioner's sugar (almost white), so in order to get four other distinct colors I mixed various amounts of icing sugar into cocoa powder in different bowls. I tried to make sufficiently distinct shades so the shading levels in the image would be visible. Starting with the lightest shade and the largest template, I carefully sifted a layer onto a white cutting board. I then carefully lifted up the stencil (this part was hard!) as to not disturb the sharp edges of the powder, and placed the next stencil on top aligned with the edges. I then sifted the next darkest color. I repeated this process for the remaining stencils and colors. I noticed as the layers got thicker, aligning and carefully removing the stencils became more important and more difficult. By the end, I had a spitting image of Dodger looking back at me!

All in all, it was a successful test run and I felt confident in my abilities for the big event!

After I made the tiramisu the night before (using the recipe above), I dusted it with a layer a cocoa powder. I then added a layer of icing sugar in the center, large enough to create the background for the image. I then repeated the process described in the previous step, building up the layers of powder. One note: add more icing sugar in the background than you think you need, as the liquid in the tiramisu begins to dissolve it immediately. You can see this happening in the final image.

While over a dozen dinner guests are not required for this instructable, it is highly recommended. The chorus of 'oos' and 'awes' as I brought out the dessert made the over-engineering of this project all worth it. "Phone eats first," as they say, but the speed at which guests were grasping for their phones to take pictures of the tiramisu was lightening fast, and frankly, a bit scary. "It's Dodger, it's actually Dodger" I heard my dad mutter with a mix of awe and what I believed to be fear. After fully crediting my university's lasercutter and the pure creativity one gets during the peak of finals-period procrastination, the guests took their final 50 photos and we cut into it. As expected from the NYT, the recipe was delicious, but I must recommend to anyone that follows this to not breathe in as your bring a slice of Dodger to your mouth. In the end, there is an 1/8" of cocoa powder on the top of the dessert which can quickly result in a ferocious coughing fit if inhaled, as a few guest will readily testify. Fortunately, this excess of cocoa power does not seem to negatively affect the quality and flavor of the dessert, if anything it makes it more sweat and more chocolatey. The final perk of this project is that I can now re-use these stencils for years to come, keeping Dodger's legacy going for longer than any sweet dog is meant to be on this earth.