I think its a lovely idea, although it might be an expensive one as the cost of ingredients, cooking time and icing can add up.
I have this for which you can get additional dividers so you can make multiple mini cakes all at the same time.
re size I would keep it fairly small as some people hate fruit cakes, and those that do often will make their own.
Last year I made the teacher and TA Nigella's christmas Cupcakes (6 each I think) that I iced and decorated and put in a gift box. I think they were well received. The few I had left over certainly tasted very nice.
Thinking about it, you might even get 3 little cakes out of a 400g tin. Think you need to wrap the tin in brown paper to stop it burning round the edges. (Oh, I don't know - it was a very long time ago!)
jackie, thanks so much. fantastic. only q in need answering, it's academic really, is if my cake will be ruined if it doesn't get cooked until tomorrow. Won't all fit in oven, so like i say, academic really.
mental note - next year i make a quick sponge cake.
Hope it all worked OK, Ernest - the link did say, after the 'filling the pans' section "Note: Cakes can be baked the next day if desired. Cover the cakes with a clean towel, foil or parchment paper and store in a cool, dry place.", so hopefully yours survived overnight :smile: