I thought I'd post this here as single parent families are generally smaller and poorer than most households. And cake is important.
I've discovered that you can freeze cake mix in cases. It cooks from frozen when you fancy home made cakes. The only thing that I will do next time is use silicon cases because they don't collapse.
I'm sure they wouldn't win GBBO prize for looks but they taste perfectly normal.
I'm going to make double quantities of muffin mix from now on and freeze then cook when needed.