According to Jim Gaffigan, a muffin is a bald cupcake.
this is going to be one of those ‘pineapple on pizza’ threads isn’t it?
Anyway, my $0.02, is that people who name something ‘bread’ even though it’s packed with sugar, are trying to upsell the healthiness of what is otherwise a cake.
Carrot cake is cake. Most Banana and Zucchini Breads (the two biggest categories in the faux-healthy category) would also be cake by sugar volume. Then again, Americans are infamous for packing even non-dessert breads with uncomfortable amounts of sugar, so I shouldn’t be surprised. See also Subway’s bread vs cake issues overseas. 
My first impulse was that bananas are generally thought of as sweet so the product is relative to that framing not so sweet, but carrots are framed as a vegetable, so relative to that frame the product is sweet.
But the zucchini bread throws that out the window. But zucchini cake alliterates better too. Still I think it is just how it rolls off the tongue with form factors following.
Quick breads differ from dessert cake in the relative amounts of fats and sugar. I have recipes for banana bread and banana cake. The former is from my workplace and the latter is from my maternal grandmother.
Banana cake is usually just made in sheet cake form but there’s no reason it can’t be done in round layers. And banana bread doesn’t usually get iced, as cake does. I have seen it with a runny glaze though.
According to Alton Brown, they’re both muffins.
Bread flour is simply wheat flour with a higher gluten content, usually because it’s made from a variety of wheat that has a higher gluten content to begin with.
Quick breads like banana bread, or carrot cake for that matter, can be made with GF grains.
I’ve heard of similar sweet breads or muffins made with beets, and even parsnips.
I’ve had coffee cake that was obviously a bread, but whoever heard of coffee bread?
Banana bread usually has more cohesion than carrot cake, in that you can hold a slice of banana bread in your hand without it falling apart. But both have less cohesion than just-plain-bread.
You can’t hold my banana bread in your hand without it falling apart, and I’ve eaten my fair share of dry carrot cake that you could barely cut with a fork.
In the majority of cases, the texture is pretty close. My banana bread is extra moist since I add one extra ripe banana and sour cream to the batter. Consistency isn’t what determines whether we call it a cake or bread.
Perhaps not in the case of the way you make it, but I definitely remember buttering a slice of banana bread on numerous occasions. That would not just be difficult with all but the driest carrot cake, but it would just be weird.
Like there’s some SI definition of cake and bread. ‘Tradition’ is a perfectly acceptable answer. It’s the answer.
Language isn’t logical.
Ultimately, the answer is that people gave them names because they thought them appropriate, not because of any categorization mania.
You fool! You don’t know what panic will ensue!
It’s a risk I’m willing to take.
The recipe I use for banana bread is pretty typical, and it calls for 1 cup of sugar (making a standard 9x5 loaf). It’s very sweet (and tasty!) but it is somewhat disconcerting to realize that you’re eating a couple of tablespoons of sugar with every slice.
I stand by this post. Banana Bread:
- Does not need to be proofed.
- Is sweet, not savory.
- Can be eaten with a fork.
- Is made from batter, not dough.
- Requires traditional cake ingredients such as eggs, butter, and sugar
It’s cake.
Q.E.D. Now all I have to do is convince the rest of the world.
Well made carrot cake has crumb like a cake. Well made banana bread has crumb more like bread. That’s why they’re called what they are
For some reason that I can’t quite articulate, this thread title reminded me of a funny story from long ago. During my college days or shortly thereafter, I took a bicycle trip on Martha’s Vineyard with a group of college friends (including SDMB’s very own kimstu). We came across a restaurant by the beach that was serving “non-alcoholic strawberry daiquiris” and “non-alcoholic strawberry margaritas”. This prompted puzzled discussion over what the difference between the two could possibly be until one of the friends said something like, “Why is everyone so confused…Isn’t the answer obvious? The non-alcholic daiquiris are made without the rum whereas the non-alcoholic margaritas are made without the tequila!” We all enjoyed that solution very much!