Mash the bananas with a fork. Sift the flour, baking powder and spice into a large bowl. Rub in the margarine until the mixture looks like fine crumbs then mix in the sugar and carrot.
Beat the honey into the banana then the eggs. Mix the wet ingredients into the dry and spoon into a loaf tin. Level the top and bake for about 1 hour until springy and firm.
Cool in the tin, then turn out, peel off the paper and cut into slices or fingers. Will keep for 3-4 days in an airtight tin. Or open-freeze, cut in slices then bag up.