This guitar cake was all about the shape. My son turned 14 last year and started taking guitar lessons. He loved playing so we got him a nice acoustic guitar for his birthday, then made a cake to match. I decided to go with a 9×13 brownie instead of a traditional cake, since I thought it would be easier to carve into the right shape without too many crumbs.
I used the “cake-like” recipe with an extra egg so it was a little higher than a regular brownie, but denser than a cake would be. I made a paper template based on the actual guitar, then cut the 9×13 brownie into the correct guitar body shape. I saved the off cuts and cut them into uniform sized pieces to extend the neck of the guitar a little longer for effect (though I opted not to do the head stock and tuners!). For frosting, I tinted butter cream using gel tints to the right brown and golden-tan, leaving the sound hole unfrosted.
I cut an extra piece of brownie nice and thin and used it for the saddle, then piped on frets and other details in brown and the strings using white…it was harder than I thought to pipe long straight lines so it didn’t come out perfect, but everyone loved it, especially the birthday boy.