chiffon cake a very light American cake, unusual because it uses oil instead of a solid fat. Flour, sugar, and baking powder are mixed together, and then oil, egg yolks, and water, with a flavouring (vanilla, lemon peel, spice), are beaten in. Finally, very stiffly whisked egg whites are folded into the mixture. The cake is baked in an oblong or ring tin.
Mariani (1994) explains that ‘chiffon pie’ first appeared in print in N. America in 1929, to be followed soon afterwards by ‘lemon chiffon’, but that chiffon cake came later and, according to one source which he cites, ‘was invented by a professional baker and introduced in May, 1948’: the first basically new cake for 100 years.