Cake cooking times

The first time you do this, you'll need to keep an eye on it. Baking times vary by a wide variety of factors, so there's no magic number that we can give you. I generally don't recommend baking by time, rather knowing what to look for in a "done" cake, be that a solid center, springy tops, browning, or pan release... depending on the cake. When I make mini cupcakes instead of full cupcakes, I know that I'll need to reduce the time by about 5-7 minutes (from ~25) but that still depends on the base recipe, how much liquid it has, how dense, etc...

So we can't give you an exact time. Also, since you're making these cakes smaller, you might consider decreasing the temperature slightly. I usually lower my oven from 350 to 325 when I'm making mini muffins.

My recommendation is to check your cakes after 20 minutes (they'll likely be underdone) but then check every 5 minutes until they start looking done to you. Fruit cakes are often more "stuff" than actual cake and they're very dense, so your recipe may not need much actual cooking to seem "done", so you'll have to use your experience to figure this out but write the time down once you get it figured out and you'll never have to worry about it again.