I was recently asked to make an unusual cake. The theme…..Mad Science! How awesome. This was really challenging. At first I envisioned a cake decorated with a dissected gumpaste frog, a beaker knocked over and the periodic table wrapped around the side of the cake. Upon reviewing this with my customer, she wanted it to be more based on physics because her son, the birthday boy, wants to be a NASA engineer one day.
Upon doing hours of brainstorming, and trying things that didn’t work, this is what I came up with. The cake displays a large atom floating above the cake, bordered by elements of the periodic table and adorned with a gumpaste composition book.
Let’s talk about how I put it all together:
- This is a 6 inch double layer chocolate cake with vanilla creme filling.
- It is resting on a 10 inch cake board.
- The cake is iced in a vanilla American Buttercream.
The floating atom is made out of gumpaste. I found the picture of an atom online, saved the pic, enlarged it on the computer then I traced it onto a piece of notebook paper from my computer screen. I know, I know, I shouldn’t have done that on my screen but I did. It was easier than printing it off and cutting it out.
I then rolled out my gumpaste to about 1/8 of an inch thick. I placed the template on top of the gumpaste and cut it out using a pastry cutter (looks like a small pizza cutter). I then let it dry completely by leaving it out on my counter-top. Gumpaste dries very fast and very hard. But do not be deceived, just because it dries hard doesn’t mean it’s not fragile. If dropped, gumpaste pieces will shatter. They become very brittle.
Once dry, I painted the black ovals on with watered down black Wilton gel color. The protons, neutrons and electrons are made from gumballs cut in half. Using a steady hand and a sharp knife, place a gumball on a cutting board and cut in half. Be careful not to cut yourself because the gumballs will slip easily. I attached the 1/2 gumball to the atom with a bit of melted chocolate. Melted chocolate will dry hard and is very strong. It works better than icing for something like this. You could use royal icing if you have it on hand. Royal Icing will also dry completely hard, almost like a glue, but it doesn’t dry as fast as melted chocolate.
I then attached two bamboo skewers to the back with melted chocolate. Attach with the pointed side down. Give it plenty of time to set and dry completely. If you are in a hurry you can pop the piece in the freezer for about 10 minutes. You never want to leave fondant/gumpaste pieces in the refrigerator or freezer. Condensation can build up in the pieces and can cause them to fall apart. Buttercream wouldn’t work well for attaching something like this because it won’t dry hard and it is made with a fat base (either butter or crisco) and this can actually cause your gumpaste piece to breakdown.
I also used the same color gumballs as the border around the cake.
Periodic Table of Elements Border
I LOVE how the elements turned out. I rolled out marshmallow fondant and cut with a square metal cutter (looks like a cookie cutter). I then painted the element’s info with watered down black Wilton color gel. Then, I attached them all around the cake with a bit of buttercream icing. Just LOVE it!
I thought it would look awesome to have a composition notebook resting on the cake board. I envisioned a Happy Birthday greeting on the composition book for the birthday boy.
I cut out a rectangle from the rolled out gumpaste (about 1/8 inch thick) and another smaller rectangle that would be used to write the greeting. I used a paint brush (**never use a paint brush that has been used with paints before, always have separate paint brushes just for your cake projects) and some watered down black Wilton gel color to paint the pattern on the notebook and the greeting.
I hope that you have enjoyed my version of a mad science cake!