The story
From its light and fluffy texture, which is said to be “so light that angels could eat it and still fly without being weighted down”.
Etymology from Wiktionary, CC BY-SA 4.0.
angel food cake
Today it means: A type of light sponge cake which originated in the United States, made with whipped egg whites (which give it an aerated texture), flour, and sugar, without butter. Full definition →