In all honesty, I would have had a much easier time if I would have started smaller and then gained experience before attempting a wrap on such large cake. But as my family would attest to, that's not my style. When I get excited about a project, I tend to jump right in and go for it.
The reason that a smaller cake would have been better to start with is that the chocolate wrap needs to be long enough to go around the circumference of the cake. A smaller wrap would be much easier to manage.
After adding the frosting, my cake measured 9.5-inches in diameter. It's very important to measure carefully because you don't want to come up short. The circumference is simply the diameter of the cake multiplied by pi (3.14). By doing this, I got 29.83-inches and proof that it's important to pay attention in geometry class. I added 2 plus inches to the circumference to get 32 since it's better to have a bit of extra wrap so that you don't come up short. Excess chocolate can be easily trimmed off.
I also measured the height of my cake which was 5.25 inches and then added an inch so that I could also trim it fit perfectly. On another note, it's essential that your cake be as level and as straight-sided as possible. This means you might have to do a bit of cake shaving before adding the frosting.
So once I had my level iced-cake and measurements, here how I made the chocolate wrap:
A sheet of parchment paper cut to fit the cake with a little extra: My measurements were 32x6.25-inches, so I used a ruler to mark these on a larger piece of parchment because I needed to leave space at the top where I could grab to lift the template up and get it around the cake. I had to tape two strips of parchment together to make it long enough. Also, tape the template onto a flat surface so that it doesn't shift while you pipe the chocolate.
Melted chocolate: You can use semi-sweet, milk, or dark chocolate. I used Callebaut dark chocolate and it's important that the chocolate not be tempered or it will set up too fast before you have time to get it around the cake. Just melt the chocolate in the microwave for 30-second intervals, stirring after each until it's thoroughly melted.
Pastry bag or parchment cone for piping: I used a disposable pastry bag and simply clipped a bit off the end for piping. Don't overfill the bag and the chocolate will be easier to control. If you wanted to use a pastry tip for even better control, I would use a #2 tip.
|I started off by piping staggered squares and then piped "v" shapes through them for added strength. Be creative with the pattern you choose but be sure it's not too delicate. You need solid connections of chocolate throughout the pattern.|
|I also cut off the excess chocolate from the top of the wrap. Cutting it to fit masks any imperfections you might have with the levelness of the cake.|
|A shell border of frosting around the base and top of the cake looks nice and helps keep the chocolate wrap locked into place.|