in volume – this may take 3-4 minutes (though i find that i usually need 5-6 minutes) in an electric mixer, depending on the speed and temperature of your eggs (always use eggs at room temperature). simple test for ribbon stage: when you lift the whisk out of the batter, some of the batter on the whisk falls back into the bowl, making distinct ‘ribbons’ before slowly disappearing into the batter.
(c) use a light hand, with quick and light folding action, when folding in the dry ingredients, as well as when folding in the oil. do not ‘slap’ the batter around in the bowl (due to a vigorous or heavy 