While the foam whips, sift the flour, salt and baking powder into
a small bowl. Rest the sieve on top to sift again later.

Remove the bowl from the mixer and scrape the foam off the whisk
attachment into a wide mixing bowl – don’t tap the whisk on the bowl
or you’ll lose precious air. Scrape the rest of the foam into the bowl.

Sift half the flour mix over the foam, then fold in gently with a balloon
whisk until it is almost all incorporated. Repeat with the remaining
flour and fold until completely mixed in. There will be a little deflation
(this is natural and fine) and the mixture will feel ‘tighter’ as you draw
your whisk through.

The flour must be added gently yet comprehensively. If the flour doesn’t
bond with the foam, you’ll get a sponge with a heavy base and an airy top.

You’ll know the flour is well incorporated when you see a little deflation
and tightness.

Scrape the fluffy batter into the prepared cake tin to sit just under
the tin lip and gently smooth the top. Bake for 30–35 minutes until
the sponge top is a pale golden colour and springy to the touch.

Because this sponge is my go-to for creams and soaks, it doesn’t matter if
I overbake. It’s better to do that than end up with a gummy-textured
underbake.

Remove from the oven. Place the tin on a wire rack to cool for
5 minutes, then gently run a knife around the edges. Flip out onto the
wire rack to complete cooling so the sponge doesn’t get schweaty
in the tin.