I've looked up a number of recipes for banana bread and zucchini bread, which I think of as pretty similar foods in terms of texture, moistness, etc. As I expected, the recipes I find online all tend to be pretty similar - same general ratios of flour, fat, sugar, eggs, and of course banana or zucchini.
The thing that surprised me is that for some reason, banana bread recipes pretty consistently call for butter, which is creamed with the sugar, whereas zucchini bread recipes invariably call for vegetable oil (presumably melted butter would work too).
I'm aware of the reasons in baking for creaming butter vs using a liquid fat. I'm wondering: what's the difference between bananas and zucchini, that one bread is usually made with solid butter, but the other not? (Or is there in fact a deliberate textural difference between "normal" banana bread and zucchini bread, which was absent in the versions I grew up with?)