I was at a meeting where they were talking about their products "selling like hotcakes." This made me curious about the etymology of the phrase. This site gives two possibilities, but nothing definitive. Does anyone know?

I'd take the simple option, that it compares it to the popularity of pancakes at a fair.

I once knew a girl nicknamed "Hotcakes" and what she was selling, everyone was buying.

It strikes me that there are many words and phrases where we don't know their origin.