My son just turned 18 and plays trumpet in several high school music ensembles, so I finally decided I would try to make him a trumpet cake.
I started with two 9×13 yellow cakes, layered and frosted in between. Using a template made from paper, I carefully cut the layered cake into a trumpet shape and put on a thin crumb coat of buttercream frosting. I saved the offcuts and eventually used on long piece in front of the cake to write the birthday message.
Someone with steadier hands than mine could do a line of music, perhaps the birthday song! But that was too ambitious for me! I put the cake into the freezer for a little while, then removed it and frosted with a very smooth layer (as smooth as I could) of buttercream, making it as flat as possible.
Since I couldn’t find silver food coloring and grey was too flat, I used a silver metallic food color spay made by Wilton. I used most of the can to spray the top and sides of my cake, reserving a little bit of the can in case I messed up, and I did.
Once the cake was “painted” silver I put it back in the freezer until the silver coating dried, about 30 minutes. In the meantime, I tinted some buttercream black with gel food color. Using a picture of another trumpet cake, I drew the trumpet outline on the cake with a toothpick, then piped it using the smallest round outliner.
My buttercream was a bit soft and my hand shook, but I was able to follow my outline. At one point I hit the edge of cake with my hand and wiped away a bunch of silver and had to smooth it and respray, and I messed up the bell shape and had to redo that, too. But ultimately, it does look like a trumpet and tasted good, too.
My two younger sons play the cello and the trombone, hopefully they won’t expect instrument cakes for their next birthdays, since the trumpet was enough of a challenge!