Pâte à Génoise Fine

Pâte à Génoise Fine (fine whole-egg sponge) teaches the central truth of sponge cake: the air you whisk into warm whole eggs is the leavening, so every fold must preserve it. There is no baking powder waiting to forgive a heavy hand. When it works, the cake stands even and butter-gold, with a close, light crumb sturdy enough for layers and tender enough to eat from the hand.

The original formula assumed a copper basin balanced over hot cinders or the hob, sixteen eggs, and a brigade that had every mould ready before the foam could wait. At home, a heatproof bowl over a barely simmering bain-marie, an electric mixer, and one 20 cm cake tin do the same work. Every ratio is quartered exactly because brigade volume and the bed of cinders are scaffolding, not the dish; the warm whisk to the ruban (ribbon stage) and the lifted spatula fold must stay. One cook, one stove, one evening.

The butter is melted, not browned, and it goes in last without bubbling. A small portion of batter lightens it before the final fold, the one home-kitchen safeguard added to keep dense butter from dropping through the foam. The step that matters most is the ruban: don't touch the flour until the batter falls from the whisk in a broad ribbon and rests visibly on the surface.