I started off the cake for the bottom tier today, it's going to be a 10 inch round fruit cake. I use Delia's recipe for my Christmas cakes, and I've adapted that for this size. I think. I mean, Delia provides the quantities for 6", 8", 9" and 11" round. I already know that an 8" round is twice the quantity of a 6" round. A 9" is 1.25 times the volume of an 8"; an 11 inch is 2 x the volume of an 8". A 10" will therefore be around 1.5 times the volume of an 8", plus a bit. The important thing will be to keep the proportions within the recipe consistent.
So, first thing is to weigh out the dried fruit, and put it in brandy to soak for at least 24 hours.
700ish grammes of Currants, 275g each of Raisins and Sultanas, 90g each of mixed peel and chopped glace cherries, and 6 tablespoons of Cognac.
It'll need at least 24 hours to soak up the brandy, which is just as well as I need to go shopping for some of the other ingredients.