Génoise (Classic French Sponge)

Prepare a 20 cm round tin: butter the base and sides, line with parchment, and butter the parchment. Set the oven to 175°C. Melt the butter and set it aside to cool to 40°C — warm enough to remain liquid, cool enough not to deflate the foam on contact. Have all other ingredients at room temperature.

Combine the eggs, sugar, and honey (if using) in a heatproof bowl set over a pan of barely simmering water. Stir continuously while heating until the mixture reaches 40–43°C — it should feel warm but not hot on the inner wrist. The warming increases the surface tension of the egg-sugar foam, permitting significantly greater air incorporation than cold eggs allow.

Remove the bowl from the bain-marie. Beat on high speed until the mixture is completely cool and at full ribbon stage: lift the beater and hold it above the bowl — the foam must fall in a thick, continuous ribbon that piles on itself and holds its shape on the surface for a counted 3 seconds before sinking. A ribbon that collapses immediately means more beating is needed. Run a finger through it; it should feel smooth and slightly cool. Any residual warmth means the beating must continue. Full volume is approximately triple the starting quantity, and the mixer sound shifts from a wet, rushing note to a lighter, almost dry tone as the foam cools and stiffens. This stage takes 8–10 minutes.

Sift the flour over the foam in three separate additions. After each addition, fold immediately with a large rubber spatula: cut down through the centre of the bowl, sweep under from the base, fold toward you, rotate the bowl a quarter turn. Count 8–10 strokes per addition — no more. Before the butter is added, the batter should appear as a pale, airy mass, light gold in colour, with visible air bubbles throughout.

This is where the dish lives or dies. Pour the melted, cooled butter in a thin stream around the edge of the bowl — never into the centre, where its greater density would sink directly through the foam, collapsing the air cells in its path. Fold with the same under-and-over motion, 6–8 strokes maximum. Stop when the butter is just incorporated, even if one or two faint butter streaks remain visible; they disappear in the oven. Every additional fold collapses cells that cannot be restored. The finished batter should still appear aerated, with a uniform pale golden colour and a visible sheen. If it looks flat and liquid rather than foam-like, too many folds were applied.

Pour the batter into the prepared tin immediately — do not allow it to rest. Place in the centre of the preheated oven. Bake at 175°C until the surface is evenly golden and springs back completely when the centre is pressed gently with one finger. A finger impression that holds for 2 or more seconds means more time is needed. A skewer inserted at the centre should emerge clean, and the edges should be pulling fractionally away from the tin sides.

Remove from the oven. Allow to cool in the tin for 5 minutes, then turn out onto a wire rack. Once fully cool, wrap tightly and rest overnight: the crumb relaxes to a noticeably more supple texture and will accept the soaking syrup with considerably greater efficiency than a freshly baked génoise. Before assembly, apply 50–60 ml of soaking syrup per layer, distributed evenly with a pastry brush; the sponge should be perceptibly moist throughout when cut but must not be wet or collapsing.