Growing up in Australia in the 80s and 90s, nearly everyone's parents had a copy of the Women's Weekly's Children's Birthday Cake recipe book.
I had multiple cakes made from it, but the most distinct one that sticks out was actually one my sister had for one of her early birthdays, it was a swimming pool that was filled with jelly and had little figures swimming in it (#18 in the link above). Mum used my Lego figures for it and I remember being very annoyed about them being dunked in jelly, so mum made that same cake for me for my 30th.
I figured for my 40th I should have another cake from the birthday cake book, and they actually have a guitar as one of them! It's an acoustic though, which I have absolutely no interest in, so I asked mum if she could make it an electric one instead, and boy did she deliver! 😂